[{"data":1,"prerenderedAt":2626},["ShallowReactive",2],{"i-kinnu:logo":3,"i-kinnu:origami-folding":8,"tile-science-core-concepts-in-biology-chemistry-of-life":12,"i-lucide:chevron-right":2621,"i-lucide:menu":2624},{"left":4,"top":4,"width":5,"height":5,"rotate":4,"vFlip":6,"hFlip":6,"body":7},0,27,false,"\u003Cg fill=\"none\">\u003Cpath d=\"M0.046875 1.05555C0.046875 1.03541 0.048197 1.01579 0.0507438 0.996728C0.0987149 0.438619 0.586845 0 1.18194 0H25.4398C26.451 0 26.9575 1.171 26.2424 1.85585L15.7301 11.9243L1.31574 0.903476C1.17475 0.79568 1.01137 0.761884 0.859586 0.784111L26.2936 25.1441C27.0086 25.829 26.5022 27 25.4909 27H1.18194C0.555061 27 0.046875 26.5133 0.046875 25.9129V1.05555Z\" fill=\"currentColor\"/>\u003C/g>",{"left":4,"top":4,"width":9,"height":10,"rotate":4,"vFlip":6,"hFlip":6,"body":11},1000,236,"\u003Cg fill=\"none\">\u003Cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n    d=\"M193.68 38.2238C195.994 38.2238 197.87 40.0989 197.87 42.412V231.812C197.87 234.125 195.994 236 193.68 236H4.19013C1.87603 236 2.02305e-07 234.125 0 231.812V42.412C-2.02305e-07 40.0989 1.87603 38.2238 4.19013 38.2238H193.68ZM111.76 89.0072C111.685 87.9474 110.572 87.2905 109.608 87.7376L96.8872 93.641C95.7786 94.1554 95.702 95.7016 96.7545 96.3225L101.579 99.167C94.7045 109.365 90.5733 122.892 90.5732 137.642C90.5733 154.323 95.8569 169.439 104.416 179.945C105.301 181.032 106.9 181.196 107.987 180.311C109.075 179.426 109.238 177.828 108.353 176.741C100.621 167.25 95.6522 153.305 95.6521 137.642C95.6522 123.661 99.6138 111.051 105.963 101.754L110.456 104.403C111.508 105.024 112.826 104.21 112.74 102.991L111.76 89.0072ZM9.63194 136.286C9.14864 136.286 8.75684 136.678 8.75684 137.161C8.7569 137.644 9.14868 138.035 9.63194 138.035H17.2161C17.6993 138.035 18.0912 137.644 18.0912 137.161C18.0912 136.678 17.6994 136.286 17.2161 136.286H9.63194ZM22.6813 136.286C22.198 136.286 21.8062 136.678 21.8062 137.161C21.8063 137.644 22.1981 138.035 22.6813 138.035H30.2655C30.7487 138.035 31.1406 137.644 31.1406 137.161C31.1406 136.678 30.7488 136.286 30.2655 136.286H22.6813ZM35.7464 136.286C35.2631 136.286 34.8713 136.678 34.8713 137.161C34.8713 137.644 35.2631 138.035 35.7464 138.035H44.4973C44.9805 138.035 45.3724 137.644 45.3724 137.161C45.3724 136.678 44.9806 136.286 44.4973 136.286H35.7464ZM49.9977 136.286C49.5144 136.286 49.1226 136.678 49.1226 137.161C49.1226 137.644 49.5144 138.035 49.9977 138.035H57.5819C58.0651 138.035 58.4569 137.644 58.457 137.161C58.457 136.678 58.0651 136.286 57.5819 136.286H49.9977ZM63.0783 136.286C62.595 136.286 62.2032 136.678 62.2032 137.161C62.2033 137.644 62.5951 138.035 63.0783 138.035H70.6625C71.1457 138.035 71.5375 137.644 71.5376 137.161C71.5376 136.678 71.1457 136.286 70.6625 136.286H63.0783ZM76.1277 136.286C75.6444 136.286 75.2526 136.678 75.2526 137.161C75.2527 137.644 75.6445 138.035 76.1277 138.035H83.7119C84.1951 138.035 84.5869 137.644 84.587 137.161C84.587 136.678 84.1951 136.286 83.7119 136.286H76.1277ZM102.266 136.286C101.782 136.286 101.39 136.678 101.39 137.161C101.391 137.644 101.782 138.035 102.266 138.035H109.85C110.333 138.035 110.725 137.644 110.725 137.161C110.725 136.678 110.333 136.286 109.85 136.286H102.266ZM115.338 136.286C114.855 136.286 114.463 136.678 114.463 137.161C114.463 137.644 114.855 138.035 115.338 138.035H122.923C123.406 138.035 123.798 137.644 123.798 137.161C123.798 136.678 123.406 136.286 122.923 136.286H115.338ZM128.403 136.286C127.92 136.286 127.528 136.678 127.528 137.161C127.528 137.644 127.92 138.035 128.403 138.035H135.988C136.471 138.035 136.863 137.644 136.863 137.161C136.863 136.678 136.471 136.286 135.988 136.286H128.403ZM141.468 136.286C140.985 136.286 140.593 136.678 140.593 137.161C140.593 137.644 140.985 138.035 141.468 138.035H149.053C149.536 138.035 149.928 137.644 149.928 137.161C149.928 136.678 149.536 136.286 149.053 136.286H141.468ZM154.541 136.286C154.058 136.286 153.666 136.678 153.666 137.161C153.666 137.644 154.058 138.035 154.541 138.035H162.125C162.609 138.035 163 137.644 163.001 137.161C163.001 136.678 162.609 136.286 162.125 136.286H154.541ZM167.614 136.286C167.131 136.286 166.739 136.678 166.739 137.161C166.739 137.644 167.131 138.035 167.614 138.035H175.198C175.681 138.035 176.073 137.644 176.073 137.161C176.073 136.678 175.681 136.286 175.198 136.286H167.614ZM180.671 136.286C180.188 136.286 179.796 136.678 179.796 137.161C179.796 137.644 180.188 138.035 180.671 138.035H188.255C188.739 138.035 189.13 137.644 189.131 137.161C189.131 136.678 188.739 136.286 188.255 136.286H180.671Z\"\n    fill=\"currentColor\" />\n  \u003Cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n    d=\"M444.85 38.2277C447.164 38.2277 449.04 40.1028 449.04 42.4159V132.928C449.04 135.241 447.164 137.116 444.85 137.116H255.36C253.046 137.116 251.17 135.241 251.17 132.928V42.4159C251.17 40.1028 253.046 38.2277 255.36 38.2277H444.85ZM361.96 125.388C361.618 125.046 361.064 125.046 360.722 125.388L354.534 131.572C354.192 131.914 354.192 132.468 354.534 132.81C354.876 133.151 355.43 133.151 355.772 132.81L361.96 126.624C362.301 126.283 362.301 125.73 361.96 125.388ZM371.047 116.311C370.705 115.969 370.15 115.969 369.809 116.311L364.446 121.671C364.104 122.012 364.104 122.567 364.446 122.908C364.788 123.249 365.342 123.25 365.684 122.908L371.047 117.548C371.388 117.207 371.388 116.652 371.047 116.311ZM380.124 107.246C379.782 106.904 379.227 106.904 378.885 107.246L373.523 112.606C373.181 112.948 373.181 113.502 373.523 113.844C373.864 114.185 374.419 114.185 374.761 113.844L380.124 108.483C380.465 108.142 380.465 107.587 380.124 107.246ZM385.736 65.8841C385.891 64.6727 384.622 63.7845 383.536 64.3434L371.069 70.7636C370.124 71.2504 369.96 72.5334 370.752 73.2424L381.2 82.5938C382.11 83.4081 383.561 82.8672 383.717 81.6557L384.393 76.3725C391.143 77.1933 398.567 80.7709 404.771 86.9711C411.124 93.3213 414.726 100.952 415.43 107.827C415.573 109.221 416.819 110.236 418.214 110.093C419.609 109.95 420.624 108.703 420.481 107.309C419.644 99.1317 415.435 90.4514 408.362 83.3817C401.466 76.489 393.038 72.3185 385.038 71.338L385.736 65.8841ZM389.2 98.1733C388.859 97.8319 388.304 97.8318 387.962 98.1733L382.6 103.534C382.258 103.875 382.258 104.429 382.6 104.771C382.941 105.112 383.496 105.112 383.838 104.771L389.2 99.4108C389.542 99.0693 389.542 98.5149 389.2 98.1733ZM398.262 89.1047C397.92 88.7633 397.365 88.7632 397.024 89.1047L391.661 94.4649C391.319 94.8065 391.319 95.3608 391.661 95.7024C392.002 96.0436 392.557 96.0438 392.899 95.7024L398.262 90.3421C398.603 90.0007 398.603 89.4463 398.262 89.1047ZM416.431 70.9616C416.089 70.6202 415.534 70.6201 415.193 70.9616L409.83 76.3218C409.488 76.6634 409.488 77.2177 409.83 77.5592C410.172 77.9005 410.726 77.9007 411.068 77.5592L416.431 72.199C416.772 71.8575 416.772 71.3032 416.431 70.9616ZM425.508 61.891C425.166 61.5496 424.611 61.5495 424.27 61.891L418.907 67.2512C418.565 67.5928 418.565 68.1471 418.907 68.4887C419.249 68.8299 419.803 68.8301 420.145 68.4887L425.508 63.1284C425.849 62.787 425.849 62.2326 425.508 61.891ZM434.569 52.8146C434.227 52.4731 433.673 52.4731 433.331 52.8146L427.968 58.1748C427.626 58.5163 427.627 59.0706 427.968 59.4122C428.31 59.7534 428.864 59.7537 429.206 59.4122L434.569 54.052C434.91 53.7105 434.91 53.1562 434.569 52.8146ZM443.638 43.7479C443.296 43.4065 442.742 43.4064 442.4 43.7479L437.037 49.1081C436.695 49.4496 436.696 50.004 437.037 50.3455C437.379 50.6868 437.933 50.687 438.275 50.3455L443.638 44.9853C443.98 44.6438 443.979 44.0895 443.638 43.7479Z\"\n    fill=\"currentColor\" />\n  \u003Cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n    d=\"M684.066 38.2277C687.798 38.2281 689.667 42.7391 687.027 45.3773L596.473 135.889C595.687 136.675 594.621 137.116 593.51 137.116H506.335C504.021 137.116 502.145 135.241 502.145 132.928V42.4159C502.145 40.1028 504.021 38.2277 506.335 38.2277H684.066ZM514.603 124.566C514.261 124.224 513.707 124.224 513.365 124.566L507.178 130.751C506.836 131.093 506.836 131.646 507.178 131.988C507.519 132.329 508.073 132.329 508.415 131.988L514.603 125.803C514.945 125.462 514.945 124.908 514.603 124.566ZM523.689 115.491C523.348 115.15 522.794 115.15 522.452 115.491L517.09 120.852C516.748 121.193 516.748 121.747 517.09 122.088C517.431 122.43 517.985 122.43 518.327 122.088L523.689 116.728C524.031 116.386 524.031 115.833 523.689 115.491ZM532.102 65.8295C530.707 65.6872 529.46 66.7017 529.318 68.0957C529.175 69.4896 530.189 70.7355 531.584 70.8787C538.463 71.5825 546.096 75.1826 552.45 81.5329C558.723 87.8037 562.312 95.3226 563.079 102.13L557.738 102.392C556.518 102.452 555.865 103.855 556.607 104.827L565.115 115.969C565.76 116.814 567.051 116.751 567.611 115.847L574.992 103.928C575.635 102.889 574.848 101.555 573.628 101.615L568.161 101.882C568.161 101.878 568.162 101.874 568.161 101.871C567.324 93.6931 563.114 85.0124 556.041 77.9425C548.968 70.873 540.283 66.6668 532.102 65.8295ZM532.766 106.421C532.425 106.079 531.871 106.079 531.529 106.421L526.166 111.781C525.825 112.123 525.825 112.676 526.166 113.018C526.508 113.359 527.062 113.359 527.403 113.018L532.766 107.657C533.108 107.316 533.108 106.762 532.766 106.421ZM541.843 97.3445C541.501 97.003 540.948 97.003 540.606 97.3445L535.243 102.705C534.901 103.046 534.902 103.6 535.243 103.941C535.585 104.283 536.139 104.283 536.48 103.941L541.843 98.5809C542.185 98.2393 542.185 97.686 541.843 97.3445ZM550.92 88.2778C550.578 87.9363 550.025 87.9363 549.683 88.2778L544.32 93.638C543.978 93.9796 543.978 94.5329 544.32 94.8745C544.662 95.2161 545.215 95.2161 545.557 94.8745L550.92 89.5142C551.262 89.1727 551.262 88.6193 550.92 88.2778ZM569.066 70.1405C568.724 69.799 568.17 69.7991 567.829 70.1405L562.466 75.5008C562.124 75.8423 562.124 76.3956 562.466 76.7372C562.808 77.0788 563.361 77.0788 563.703 76.7372L569.066 71.377C569.407 71.0354 569.407 70.4821 569.066 70.1405ZM578.143 61.0699C577.801 60.7284 577.247 60.7285 576.906 61.0699L571.543 66.4302C571.201 66.7717 571.201 67.3251 571.543 67.6666C571.885 68.0082 572.438 68.0082 572.78 67.6666L578.143 62.3064C578.484 61.9648 578.484 61.4115 578.143 61.0699ZM587.219 51.9896C586.878 51.6481 586.324 51.6481 585.982 51.9896L580.62 57.3498C580.278 57.6914 580.278 58.2447 580.62 58.5863C580.961 58.9279 581.515 58.9279 581.857 58.5863L587.219 53.2261C587.561 52.8845 587.561 52.3312 587.219 51.9896ZM596.288 42.9249C595.947 42.5833 595.392 42.5833 595.05 42.9249L589.689 48.2851C589.347 48.6267 589.347 49.18 589.689 49.5216C590.03 49.863 590.584 49.8631 590.926 49.5216L596.288 44.1613C596.63 43.8198 596.63 43.2664 596.288 42.9249Z\"\n    fill=\"currentColor\" />\n  \u003Cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n    d=\"M850.814 38.2277C854.547 38.2281 856.416 42.739 853.777 45.3773L763.223 135.889C762.437 136.674 761.371 137.116 760.26 137.116H673.176C669.443 137.116 667.574 132.605 670.213 129.966L760.768 39.4544C761.554 38.6692 762.62 38.2277 763.731 38.2277H850.814ZM761.338 121.8C760.855 121.8 760.463 122.191 760.463 122.674V131.13H762.213V122.674C762.213 122.191 761.821 121.8 761.338 121.8ZM761.338 108.971C760.855 108.971 760.463 109.363 760.463 109.846V118.301H762.213V109.846C762.213 109.363 761.821 108.971 761.338 108.971ZM761.338 96.1402C760.855 96.1406 760.463 96.5321 760.463 97.0149V105.47H762.213V97.0149C762.213 96.532 761.821 96.1404 761.338 96.1402ZM782.263 71.887C781.043 71.951 780.395 73.3571 781.139 74.3257L784.474 78.6631C779.115 82.951 771.242 85.7443 762.35 85.7444C753.366 85.7442 745.421 82.8944 740.059 78.5305C738.972 77.6461 737.373 77.8099 736.488 78.8961C735.602 79.983 735.766 81.582 736.853 82.467C743.231 87.6574 752.348 90.8207 762.35 90.8209C772.209 90.8208 781.205 87.746 787.568 82.6884L790.833 86.9341C791.577 87.9025 793.103 87.6391 793.479 86.4767L797.791 73.138C798.118 72.127 797.33 71.1017 796.268 71.1566L782.263 71.887ZM761.338 70.4847C760.855 70.4851 760.463 70.8767 760.463 71.3594V79.8147H762.213V71.3594C762.213 70.8766 761.821 70.485 761.338 70.4847ZM761.338 57.656C760.855 57.6564 760.463 58.048 760.463 58.5307V66.986H762.213V58.5307C762.213 58.0479 761.821 57.6563 761.338 57.656ZM761.338 44.8293C760.855 44.8297 760.463 45.2212 760.463 45.704V54.1592H762.213V45.704C762.213 45.2211 761.821 44.8295 761.338 44.8293Z\"\n    fill=\"currentColor\" />\n  \u003Cpath\n    d=\"M995.759 38.2277C999.53 38.228 1001.42 42.5171 998.752 45.0253L959.55 81.9005L905.796 41.5363C905.271 41.1418 904.662 41.0182 904.096 41.0994L997.485 130.319C1000.15 132.828 998.262 137.116 994.491 137.116H905.298C902.96 137.116 901.065 135.333 901.065 133.134V42.0941C901.065 42.0204 901.07 41.9483 901.079 41.8786C901.258 39.8345 903.079 38.2277 905.298 38.2277H995.759Z\"\n    fill=\"currentColor\" />\n  \u003Cpath\n    d=\"M505.873 0C506.657 4.57042e-05 507.307 0.195499 507.823 0.587023C508.338 0.969046 508.596 1.53802 508.596 2.29251C508.596 2.76034 508.467 3.19015 508.209 3.58162C507.951 3.96344 507.497 4.26401 506.848 4.48361V4.54114C507.65 4.67487 508.205 4.96191 508.51 5.4012C508.816 5.83087 508.969 6.31772 508.969 6.86193C508.969 7.74056 508.672 8.41851 508.08 8.89604C507.497 9.38304 506.733 9.62731 505.787 9.62738C504.861 9.62738 504.158 9.42172 503.68 9.0111C503.212 8.60054 502.935 8.08005 502.849 7.44993L503.881 7.10571L503.924 7.24028C504.035 7.54934 504.211 7.82925 504.454 8.07986C504.731 8.36635 505.166 8.50986 505.758 8.50989C506.465 8.50989 506.943 8.32772 507.191 7.9648C507.449 7.6019 507.579 7.20078 507.579 6.7615C507.579 6.2173 507.378 5.80683 506.977 5.52992C506.585 5.25295 505.93 5.10026 505.013 5.07161V4.15402C505.901 4.12537 506.489 3.92484 506.776 3.55237C507.062 3.18009 507.206 2.82242 507.206 2.47876C507.206 1.62801 506.752 1.17539 505.845 1.12237L505.658 1.11749C505.467 1.11752 505.242 1.14605 504.985 1.2033C504.736 1.25105 504.511 1.3274 504.31 1.43245L504.081 2.56457L503.05 2.44951L503.322 0.687461C503.666 0.49653 504.068 0.33454 504.526 0.200875C504.985 0.0671945 505.434 0 505.873 0Z\"\n    fill=\"currentColor\" />\n  \u003Cpath\n    d=\"M905.727 2.30616L904.638 2.4066L904.466 1.26083H901.428V3.72497C901.533 3.71544 901.643 3.71034 901.757 3.71034H902.086C902.755 3.71034 903.386 3.78668 903.979 3.93949C904.58 4.09229 905.068 4.38363 905.44 4.8132C905.822 5.23335 906.014 5.84949 906.014 6.66106C906.014 7.64468 905.722 8.38068 905.14 8.86776C904.557 9.36434 903.783 9.6127 902.818 9.61275C901.91 9.61275 901.213 9.40711 900.725 8.99648C900.248 8.59544 899.96 8.08007 899.865 7.44993L900.911 7.10571C901.007 7.49723 901.203 7.8271 901.499 8.09449C901.795 8.37131 902.211 8.50985 902.746 8.50989C903.395 8.50989 903.869 8.33787 904.165 7.99405C904.461 7.65981 904.609 7.22507 904.609 6.69031C904.609 5.87861 904.337 5.3625 903.792 5.14279C903.248 4.91361 902.612 4.79958 901.886 4.79955C901.695 4.79955 901.489 4.80365 901.27 4.8132C901.059 4.82275 900.854 4.83701 900.653 4.85611L900.224 4.44071V0.143343H905.569L905.727 2.30616Z\"\n    fill=\"currentColor\" />\n  \u003Cpath fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n    d=\"M765.49 6.04576H766.966L766.837 7.14862H765.49V9.48404H764.185V7.14862H759.857L759.713 6.04576L762.909 0.143343H765.49V6.04576ZM760.96 6.04576H764.185V1.26083H763.541L760.96 6.04576Z\"\n    fill=\"currentColor\" />\n  \u003Cpath d=\"M4.80573 6.47481H6.41154V7.60693H1.81068V6.47481H3.50235V1.27546H1.81068V0.143343H4.80573V6.47481Z\"\n    fill=\"currentColor\" />\n  \u003Cpath\n    d=\"M254.359 0C255.353 0 256.055 0.239186 256.466 0.716715C256.877 1.18447 257.083 1.68072 257.083 2.20573C257.083 2.85516 256.849 3.44346 256.38 3.96875C255.912 4.49397 255.348 4.96638 254.689 5.38657C254.039 5.79717 253.437 6.15968 252.883 6.47481H256.423L256.538 5.42948L257.599 5.51529L257.426 7.60693H251.407L251.292 6.58987C252.582 5.73032 253.638 4.98523 254.46 4.35489C255.281 3.71509 255.693 3.05632 255.693 2.37832C255.693 1.53787 255.166 1.11749 254.115 1.12237L254.115 1.11749C253.924 1.11754 253.695 1.14604 253.427 1.2033C253.16 1.25104 252.916 1.32238 252.697 1.41783L252.467 2.47876L251.45 2.3637L251.707 0.60165C252.118 0.401088 252.563 0.253475 253.041 0.15797C253.519 0.0529708 253.958 1.99446e-05 254.359 0Z\"\n    fill=\"currentColor\" />\u003C/g>",{"tile":13,"orbsWithOnlyMarkdownPages":980},{"id":14,"data":15,"type":16,"maxContentLevel":19,"version":20,"orbs":21},"1caa0c32-186e-42df-b298-9df71cd80ffa",{"type":16,"title":17,"tagline":18},9,"Chemistry of Life","The chemical building blocks of organisms",3,4,[22,164,346,493,634,773],{"id":23,"data":24,"type":25,"version":25,"maxContentLevel":19,"summaryPage":27,"introPage":36,"pages":43},"46e88a40-dd68-4cc7-9f9c-93cfad8e49ea",{"type":25,"title":26},2,"The Role of Carbon",{"id":28,"data":29,"type":19,"maxContentLevel":19,"version":35},"f5db6966-0f8c-438b-b66b-718804d2842d",{"type":19,"summary":30},[31,32,33,34],"Carbon forms stable bonds with many elements, including itself.","Carbon's four bonds enable complex, life-essential molecules.","Carbohydrates showcase carbon's role in energy and structure.","Carbon's versatility is what drives the diversity of life on Earth.",1,{"id":37,"data":38,"type":39,"maxContentLevel":19,"version":35},"2cb8e1a3-5067-47de-9f69-d0b978f1081c",{"type":39,"intro":40},10,[41,42],"Why is carbon called the backbone of life?","How do carbon's bonds create molecular diversity?",[44,62,100,128],{"id":45,"data":46,"type":35,"maxContentLevel":19,"version":35,"reviews":49},"99e4dd4f-4fe8-4f31-a2cb-337960db7be0",{"type":35,"markdownContent":47,"audioMediaId":48},"All life on Earth is composed of chemicals arranged in specific structures. While the periodic table includes many elements, only a particular subset—like carbon, hydrogen, oxygen, and nitrogen—plays a central role in the chemistry of life, forming stable and complex molecules that are essential for biological processes.\n\nThis tile will track through the chemical compositions that make up living organisms, starting with perhaps the most important of all: **carbon**.\n\n![Graph](image://e6cfe26e-c0ba-4299-b113-a72a11f23a2b \"Graphene. Image by AlexanderAlUS (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")\n\nThe image above is a graphical representation of a kind of structure known as **graphene**, an extraordinary material made of a single layer of carbon atoms. The carbon atoms are arranged in a hexagonal lattice, resembling a honeycomb.\n\nDespite being only one atom thick, graphene is incredibly strong, lightweight, and highly conductive, and these days it is being used in cutting-edge technologies, such as nanoscale machines, ultra-sensitive sensors, and advanced electronic devices.\n\nBut long before these technologies, nature used the unique properties of **carbon** to build life.","1dabfafa-31cc-4606-907a-ccdeb8787c66",[50],{"id":51,"data":52,"type":53,"version":35,"maxContentLevel":19},"dc42fe6c-8760-4a9d-a613-2233fa8b1146",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":54,"multiChoiceCorrect":56,"multiChoiceIncorrect":58,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},11,[55],"What is the structure of graphene?",[57],"Single layer of carbon atoms, arranged in a hexagonal lattice",[59,60,61],"Multiple layers of carbon atoms, arranged in a cubic lattice","Single layer of carbon atoms, arranged in a triangular lattice","Multiple layers of carbon atoms, arranged in a hexagonal lattice",{"id":63,"data":64,"type":35,"maxContentLevel":19,"version":25,"reviews":67},"8187c65b-2d69-43c5-b5e3-dcc847c490fc",{"type":35,"markdownContent":65,"audioMediaId":66},"Carbon is a fundamental element in the chemistry of life, acting as the backbone for a wide variety of biological molecules.\n\n![Graph](image://b5c00ee2-9660-407a-b681-9d447fe8a8aa \"Pure Carbon by Texas Lane (CC BY-SA 4.0) \u003Chttps://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons\")\n\nThis is because carbon has a unique ability to **form stable bonds** with many other elements, including with itself. This characteristic allows for the creation of complex molecules essential for life, such as **proteins**, **nucleic acids**, **carbohydrates**, and **lipids**.\n\nSpecifically, carbon atoms can form **four covalent bonds** with other atoms. This means that a single carbon atom can connect with up to four other atoms, creating a three-dimensional structure.\n\nFor example, in a methane molecule (**CH4**), carbon forms four bonds with hydrogen atoms, which gives the molecule a stable structure.\n\n![Graph](image://682cefc4-866c-4e4b-93d8-eac6b4cbb229 \"Methane (CH4). Image: DynaBlast, CC BY-SA 2.5 \u003Chttps://creativecommons.org/licenses/by-sa/2.5>, via Wikimedia Commons\")\n\nThis ability to form multiple bonds makes carbon incredibly versatile, allowing it to be the foundation for large and complex molecules, known as macromolecules.","ad7a2d95-91d3-44db-8203-66e186aea998",[68,79],{"id":69,"data":70,"type":53,"version":25,"maxContentLevel":19},"7824db47-4f0d-43ef-8df8-a0fc28edd468",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":71,"multiChoiceCorrect":73,"multiChoiceIncorrect":75,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[72],"What is a key characteristic of carbon that allows for the creation of complex molecules essential for life?",[74],"Forms stable bonds with many elements",[76,77,78],"Forms unstable bonds with many elements","Forms stable bonds with only a few elements","Cannot form bonds with other elements",{"id":80,"data":81,"type":53,"version":35,"maxContentLevel":19},"6502c142-3cda-412d-8934-504f7a029002",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":82,"multiChoiceQuestion":86,"multiChoiceCorrect":88,"multiChoiceIncorrect":90,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":94,"matchPairsPairs":96},[83,84,85],"a5bd75d3-d96e-4e37-978b-239b5ea75f94","5bbc4aa2-2f8b-48b7-8173-f7e32890eb79","82ee88fe-76ee-418c-ac47-f64c23ce3968",[87],"How many covalent bonds can a single carbon atom form?",[89],"Four",[91,92,93],"Two","Three","Five",[95],"Match the pairs below:",[97],{"left":98,"right":99,"direction":19},"Carbon","Can form four covalent bonds",{"id":101,"data":102,"type":35,"maxContentLevel":19,"version":35,"reviews":105},"d315d97d-143c-4cd6-b1a9-b7b8f7f6bcbc",{"type":35,"markdownContent":103,"audioMediaId":104},"Carbon's ability to form double and triple bonds with other carbon atoms adds another layer of diversity to molecules. These types of bonds change the shape and properties of the molecules. For example, double bonds make a molecule more rigid and less flexible, affecting how it behaves and reacts with other substances.\n\nIn addition to bonding with other carbon atoms, carbon can also form stable bonds with elements like **oxygen**, **nitrogen**, **sulfur**, and **phosphorus**.\n\nWhen carbon bonds with these elements, it creates **functional groups**, which are specific clusters of atoms that give a molecule certain properties and make it behave in a predictable way.\n\nFunctional groups are important because they determine how a molecule interacts in chemical reactions. For example:\n\n- The **hydroxyl group** (–OH) makes a molecule more likely to dissolve in water.\n- The **carboxyl group** (–COOH) makes a molecule acidic, like in fatty acids.\n\nThese functional groups are essential for processes in living organisms, such as metabolism, gene expression, and cell communication.","e0c92515-834f-45d4-b05f-1445c0a34267",[106,113],{"id":107,"data":108,"type":53,"version":35,"maxContentLevel":19},"59838fb0-8063-40a4-8283-2e2347a913ce",{"type":53,"reviewType":35,"spacingBehaviour":35,"activeRecallQuestion":109,"activeRecallAnswers":111},[110],"What are 'functional groups'?",[112],"Groups of atoms bonded to carbon that give molecules specific chemical properties (e.g. acidity or interaction with water)",{"id":114,"data":115,"type":53,"version":35,"maxContentLevel":19},"9719e4db-b9e0-4914-8892-5c8e799dff43",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":116,"multiChoiceCorrect":118,"multiChoiceIncorrect":123,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[117],"What elements are common in the creation of functional groups?",[119,120,121,122],"Oxygen","Nitrogen","Phosphorus","Sulfur",[124,125,126],"Helium","Neon","Lead",true,{"id":129,"data":130,"type":35,"maxContentLevel":19,"version":35,"reviews":133},"0733fcce-90c5-4326-9029-6c038a83b0ab",{"type":35,"markdownContent":131,"audioMediaId":132},"**Carbohydrates** are a prime example of the complexity and diversity that carbon can create in biological systems.\n\n![Graph](image://8799a3cf-65d4-4572-ba2d-a5210fb4132e \"The chemical composition of glucose (a corbohydrate) made of carbon (C), oxygen (O) and hydrogen (H). Image: Ben; Yikrazuul, Public domain, via Wikimedia Commons\")\n\nCarbohydrates are composed of **carbon**, **hydrogen**, and **oxygen**, and they play crucial roles in energy storage, structural integrity, and cellular communication in living organisms.\n\n**Simple carbohydrates**, like glucose, serve as a primary energy source for cells.\n\nWhen multiple glucose molecules bond together, they can form **complex carbohydrates**, such as **starch** and **cellulose**, which are essential for energy storage in plants and structural support in plant cell walls, respectively.\n\nHumans and other animals consume **starchy plants**, like **potatoes**, to access this stored energy, breaking down the starch into glucose for use in metabolic processes.\n\n![Graph](image://09526bc1-e406-46b1-a7ea-a0b332d8443b \"Potato and cross section (GFDL 1.2) \u003Chttp://www.gnu.org/licenses/old-licenses/fdl-1.2.html>, via Wikimedia Commons\")","6394d1c1-e7cf-40aa-b36b-0f1d53c90d2a",[134,147],{"id":135,"data":136,"type":53,"version":35,"maxContentLevel":19},"be1baf8b-6ee3-4561-8a51-eef3871cfebe",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":137,"multiChoiceCorrect":139,"multiChoiceIncorrect":143,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[138],"Which statements apply to cellulose?",[140,141,142],"Formed by multiple glucose molecules","Provides structural support in plant cell walls","Complex carbohydrate",[144,145,146],"Primary energy source for cells","Essential for energy storage in plants","Simple carbohydrate",{"id":148,"data":149,"type":53,"version":35,"maxContentLevel":19},"b66948d6-c9c8-429b-8d5b-e652fb802791",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":150,"multiChoiceQuestion":154,"multiChoiceCorrect":156,"multiChoiceIncorrect":158,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":161,"matchPairsPairs":162},[151,152,153],"ae30301a-a7e9-41d7-9cf0-329cf273ee2b","a663a8c4-c303-4864-a6fb-031af06e5850","e116e165-e5aa-467b-aa03-5723877b6de0",[155],"Which simple carbohydrate is the primary source of stored chemical energy for cells?",[157],"Glucose",[159,160],"Starch","Cellulose",[95],[163],{"left":157,"right":144,"direction":19},{"id":165,"data":166,"type":25,"version":35,"maxContentLevel":19,"summaryPage":168,"introPage":177,"pages":183},"4f1a3325-355e-471c-b19e-1561f779d913",{"type":25,"title":167},"Proteins",{"id":169,"data":170,"type":19,"maxContentLevel":19,"version":35},"07d186e0-23d0-4819-818e-01b7a30d2188",{"type":19,"summary":171},[172,173,174,175,176],"Proteins are chains of amino acids determining shape and function.","Enzymes are proteins that speed up essential chemical reactions.","Structural proteins like collagen and keratin provide cell support.","Antibodies are proteins that protect the body from infections.","Proteins transport substances and facilitate cell signaling",{"id":178,"data":179,"type":39,"maxContentLevel":19,"version":35},"b4ff04d3-a56c-4ea0-b64f-e2d5a65764c0",{"type":39,"intro":180},[181,182],"What are proteins made of?","How do enzymes speed up reactions?",[184,246,293,314],{"id":185,"data":186,"type":35,"maxContentLevel":19,"version":35,"reviews":189},"f011e2d6-7b5a-4fce-b4b0-748854ed7320",{"type":35,"markdownContent":187,"audioMediaId":188},"Proteins are essential molecules that play a crucial role in the characteristics of life. They are made up of smaller units called amino acids, which are linked together in long chains.\n\n![Graph](image://68d85488-06f0-4c92-8c50-c6985bf46ee3 \"A long protein chain (CC BY-SA 4.0) \u003Chttps://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons\")\n\nThe **sequence** of these amino acids determines the protein's shape and function.\n\nProteins are involved in almost every process within living organisms, making them vital for life.\n\nOne of the primary roles of proteins is to act as enzymes. **Enzymes** are proteins that speed up chemical reactions in the body, which is essential for metabolism. Without enzymes, reactions would occur too slowly to sustain life.\n\nFor example, digestive enzymes help break down food into nutrients that the body can use for energy, growth, and repair.","d2c72ae7-f3f6-49f6-a6dd-ff47b384ef94",[190,207,227],{"id":191,"data":192,"type":53,"version":35,"maxContentLevel":19},"a3966c62-685e-42e2-956e-979e5c38e234",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":193,"multiChoiceQuestion":196,"multiChoiceCorrect":197,"multiChoiceIncorrect":199,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":203,"matchPairsPairs":204},[194,195],"0547cb2c-eaa9-45f3-a2ba-67b3348ba0ff","023f7e19-c1b4-49d1-8b77-2f35113274e8",[181],[198],"Amino acids in long chains",[200,201,202],"Fatty acids in long chains","Nucleotides in short chains","Carbon in a lattice",[95],[205],{"left":167,"right":206,"direction":19},"Made of amino acids in long chains",{"id":208,"data":209,"type":53,"version":35,"maxContentLevel":19},"d3fc9096-e2ab-4db1-8356-0839cbc4be46",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":210,"multiChoiceQuestion":214,"multiChoiceCorrect":216,"multiChoiceIncorrect":218,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":222,"matchPairsPairs":223},[211,212,213],"7eaf435d-ec13-4bfe-8a81-4c5ae58fd704","ac27cf67-00ff-4a09-96d5-f986b635e5d5","4e48d196-2d73-464a-a6fa-70b9b74ace54",[215],"What are enzymes?",[217],"Proteins that speed up chemical reactions",[219,220,221],"Proteins that provide structural support","Proteins that transport substances","Proteins that transmit messages into the cell",[95],[224],{"left":225,"right":226,"direction":19},"Enzyme protein","Speeds up chemical reactions",{"id":228,"data":229,"type":53,"version":35,"maxContentLevel":19},"14ccef0c-b96d-4498-9811-f8a3951a3bb0",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":230,"multiChoiceQuestion":233,"multiChoiceCorrect":235,"multiChoiceIncorrect":237,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":241,"matchPairsPairs":242},[231,232],"b41bce7c-2dda-441b-80da-dcd35a566684","7254f19e-b494-411b-b5d8-9d95e48c636c",[234],"What determines the shape and function of a protein?",[236],"The sequence of amino acids",[238,239,240],"The temperature of the environment","Regulatory hormones","The type of cell",[95],[243],{"left":244,"right":245,"direction":19},"Amino Acids","Their sequence determines the shape and function of a protein",{"id":247,"data":248,"type":35,"maxContentLevel":19,"version":35,"reviews":251},"c8db2f4f-180e-478c-b56b-94dc0221cc4d",{"type":35,"markdownContent":249,"audioMediaId":250},"Proteins also provide structural support to cells and tissues. For instance, **collagen** is a protein that gives strength and structure to skin, bones, and connective tissues.\n\n![Graph](image://2a25ce6e-062a-4ec9-b26c-ccd89726309f \"Collagen. Image by Laboratoires Servier (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")\n\n**Keratin**, another protein, is found in hair, nails, and the outer layer of skin, providing protection and durability.\n\nThese structural proteins help maintain the shape and integrity of cells and tissues, which is crucial for the proper functioning of an organism.\n\n**Transport proteins** are another important type of protein. They help move substances across cell membranes and throughout the body.\n\n**Hemoglobin**, a transport protein in red blood cells, carries oxygen from the lungs to the rest of the body and brings carbon dioxide back to the lungs for exhalation. This transport of gases is vital for respiration and energy production in cells.\n\n![Graph](image://1ef4516d-d3be-4262-b9fe-cbca8532502b \"Hemoglobin (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons\")","56c41105-18d8-482f-bb2a-962ec95a228a",[252,266,281],{"id":253,"data":254,"type":53,"version":35,"maxContentLevel":19},"6cf38aad-652a-462d-8f21-433ca764e95b",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":255,"multiChoiceCorrect":257,"multiChoiceIncorrect":263,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[256],"What role do proteins play in cells and tissues?",[258,259,260,261,262],"Structural support","Act as enzymes","Transport substances","Cell signaling","Immune response",[264,265],"Store genetic information","Produce energy",{"id":267,"data":268,"type":53,"version":35,"maxContentLevel":19},"ce2349cb-bc94-4ea7-9570-c618f2704da1",{"type":53,"reviewType":269,"spacingBehaviour":35,"matchPairsQuestion":270,"matchPairsPairs":271,"matchPairsShowExamples":6},6,[95],[272,275,278],{"left":273,"right":274,"direction":19},"Transport proteins","Move substances across cell membranes",{"left":276,"right":277,"direction":19},"Keratin","Found in hair, nails, outer skin layer",{"left":279,"right":280,"direction":19},"Collagen","Provides strength to connective tissues (such as in skin and bones)",{"id":282,"data":283,"type":53,"version":35,"maxContentLevel":19},"91bfaceb-d0bb-4749-b517-3ca31c054547",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":284,"multiChoiceCorrect":286,"multiChoiceIncorrect":289,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[285],"What are the specific functions of the protein hemoglobin?",[287,288],"Carries oxygen in red blood cells","Brings carbon dioxide back to lungs",[290,291,292],"Regulates blood sugar","Neutralizes foreign invaders","Provides structural support",{"id":294,"data":295,"type":35,"maxContentLevel":19,"version":35,"reviews":298},"168b8cb9-36de-48af-bbb3-c8d42751f135",{"type":35,"markdownContent":296,"audioMediaId":297},"Proteins also play a key role in cell signaling and communication.\n\n**Receptor proteins** on the surface of cells bind to **signaling molecules**, such as hormones, and transmit messages into the cell.\n\nThis process helps cells respond to changes in their environment and coordinate activities within the organism.\n\nFor example, insulin is a **regulatory protein** or **hormone**, that controls blood sugar levels by signaling cells to take up glucose.\n\nIn addition to these roles, proteins are involved in the immune response.\n\n**Antibodies** are proteins that recognize and neutralize foreign invaders, such as bacteria and viruses, protecting the body from infections. This defense mechanism is essential for maintaining health and preventing disease.","bebd7bf1-debb-43f4-b6f2-e45c77b4fc4e",[299],{"id":300,"data":301,"type":53,"version":35,"maxContentLevel":19},"6fb28a85-7eb2-403d-8b5e-93654b80d437",{"type":53,"reviewType":269,"spacingBehaviour":35,"matchPairsQuestion":302,"matchPairsPairs":304,"matchPairsShowExamples":6},[303],"Match the type of protein to its function below:",[305,308,311],{"left":306,"right":307,"direction":19},"Antibodies","Recognize and neutralize foreign invaders, protecting the body from infections",{"left":309,"right":310,"direction":19},"Receptor proteins","Bind to signalling molecules and transmit messages into the cell",{"left":312,"right":313,"direction":19},"Insulin","Controls blood sugar levels by signaling cells to take up glucose.",{"id":315,"data":316,"type":35,"maxContentLevel":19,"version":35,"reviews":319},"40eed6ae-afa3-47a8-93bd-232192115c30",{"type":35,"markdownContent":317,"audioMediaId":318},"Proteins are incredibly versatile because they can fold into a wide variety of shapes, allowing them to interact specifically with other molecules.\n\nThis specificity is crucial for the regulation of cellular processes.\n\nFor example, **enzymes** have active sites that bind to specific substrates, ensuring that biochemical reactions occur with precision and efficiency.\n\nMoreover, proteins can change their shape in response to environmental conditions or interactions with other molecules.\n\nThese changes can activate or deactivate the protein's function, providing a mechanism for regulating cellular activities.\n\nFor instance, the binding of a hormone to its receptor can trigger a series of events inside the cell, leading to a specific response.","ac7632ee-1097-40c4-a394-15227de4f1ba",[320,338],{"id":321,"data":322,"type":53,"version":35,"maxContentLevel":19},"e8d8441a-17b5-435a-83a4-6a848eb463e5",{"type":53,"reviewType":269,"spacingBehaviour":35,"matchPairsQuestion":323,"matchPairsPairs":325,"matchPairsShowExamples":6},[324],"Match the protein type to an example of that type:",[326,329,332,335],{"left":327,"right":328,"direction":19},"Enzymes","Digestive proteins that break down food",{"left":330,"right":331,"direction":19},"Structural Proteins","Collagen and keratin",{"left":333,"right":334,"direction":19},"Transport Proteins","Hemoglobin",{"left":336,"right":337,"direction":19},"Regulatory Proteins","Insulin ",{"id":339,"data":340,"type":53,"version":35,"maxContentLevel":19},"11d76885-1ea9-4449-ae1c-066519ae9043",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":341,"multiChoiceCorrect":343,"multiChoiceIncorrect":345,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[342],"Which of the following are examples of signaling molecules?",[344],"Hormones",[279,276,334],{"id":347,"data":348,"type":25,"version":19,"maxContentLevel":19,"summaryPage":350,"introPage":358,"pages":364},"2d49d7c4-43c2-4602-8cd5-3653fac77ff5",{"type":25,"title":349},"Carbohydrates",{"id":351,"data":352,"type":19,"maxContentLevel":19,"version":35},"2e3a5a94-2f00-4b5e-b2a8-6b4f3c476db5",{"type":19,"summary":353},[354,355,356,357],"Carbs power cells by breaking down into glucose.","Starches and glycogen store energy for later use.","Cellulose gives plants strength and structure.","Glycoproteins help cells recognize and communicate.",{"id":359,"data":360,"type":39,"maxContentLevel":19,"version":35},"b45d9644-2fd4-4fa9-8315-44bb984cbf26",{"type":39,"intro":361},[362,363],"How do plants store energy using carbohydrates?","What role does cellulose play in plant structure?",[365,411,441,462],{"id":366,"data":367,"type":35,"maxContentLevel":19,"version":35,"reviews":370},"0bf094f0-209b-42d2-b596-c87bbaaf1f9a",{"type":35,"markdownContent":368,"audioMediaId":369},"We already touched upon carbohydrates in the orb focused on **carbon.** This section is going to go into a little more depth.\\\n\\\nCarbohydrates are essential molecules that play a crucial role in the characteristics of life, particularly in energy processing, growth and development, and response to stimuli.\n\nThey are composed of **carbon**, **hydrogen**, and **oxygen**, and are found in foods like fruits, vegetables, grains, and dairy products.\n\n![Graph](image://b52cfb6d-8ae1-4993-b5ce-e5488a484d5f \"Assorted grains. Image by Fir0002 (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons\")\n\nOne of the primary roles of carbohydrates is to provide energy.\n\n**Simple carbohydrates**, such as glucose, are quickly absorbed by the body and used as a direct source of energy. **Glucose** is especially important because it is the main fuel for our cells.\n\nDuring **cellular respiration**, glucose is broken down to produce adenosine triphosphate (ATP), which cells use to power various activities, such as muscle contraction and nerve function.\n\nThis immediate energy supply is vital for everyday activities and overall bodily functions.","7d17ef3b-a57f-4126-8293-fb3d5765dca5",[371,380,393],{"id":372,"data":373,"type":53,"version":35,"maxContentLevel":19},"0bb86072-cd0e-43cd-ba77-1f57ce756b0b",{"type":53,"reviewType":25,"spacingBehaviour":35,"binaryQuestion":374,"binaryCorrect":376,"binaryIncorrect":378},[375],"What is the composition of carbohydrate?",[377],"Composed of carbon, hydrogen, and oxygen",[379],"Composed of carbon and hydrogen",{"id":381,"data":382,"type":53,"version":35,"maxContentLevel":19},"a64ab6dd-a2fd-436c-9986-cfa56be06eb8",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":383,"multiChoiceCorrect":385,"multiChoiceIncorrect":389,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[384],"Which of the following statements are true about simple carbohydrates?",[386,387,388],"Quickly absorbed by the body","Used as a direct source of energy","Glucose is an example",[390,391,392],"Slowly absorbed by the body","Used for long-term energy storage","Starch is an example",{"id":394,"data":395,"type":53,"version":35,"maxContentLevel":19},"3421a474-8c79-4616-bbf0-06e05a0d88ec",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":396,"multiChoiceQuestion":399,"multiChoiceCorrect":401,"multiChoiceIncorrect":403,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":407,"matchPairsPairs":408},[397,398],"70286092-01dd-448a-ae4c-16d071d29651","41969ac0-f2c8-43d6-8265-9a6482d02147",[400],"What is cellular respiration?",[402],"Process where glucose is broken down to produce ATP",[404,405,406],"Process where ATP is converted to glucose","Process where oxygen is produced","Process where proteins are synthesized",[95],[409],{"left":410,"right":402,"direction":19},"Cellular Respiration",{"id":412,"data":413,"type":35,"maxContentLevel":19,"version":25,"reviews":416},"b815d990-f483-463a-8d19-af614a9fa991",{"type":35,"markdownContent":414,"audioMediaId":415},"Carbohydrates also come in more complex forms, such as starches and glycogen, which serve as energy storage molecules.\n\n**Plants store energy in the form of starch**, which is found in foods like potatoes, rice, and corn.\n\n![Graph](image://b990e2f8-0991-4147-94a2-a39d1dbe387d \"Cornstarch mixed with water. Image by kalaya (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")\n\nWhen we eat these foods, our bodies break down the starch into glucose, which can then be used for energy.\n\nAnimals, including humans, **store energy in the form of glycogen**, primarily in the liver and muscles.\n\nWhen the body needs energy, glycogen is broken down into glucose to maintain blood sugar levels and provide fuel for cells.\n\nThis stored energy is crucial for sustaining bodily functions during periods when food intake is low.","93f934ca-5c29-410b-ae20-02b2ce792a90",[417,430],{"id":418,"data":419,"type":53,"version":35,"maxContentLevel":19},"ccd7e5dc-2ebb-4f9c-bc3d-9ee5ca1841da",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":420,"multiChoiceCorrect":422,"multiChoiceIncorrect":426,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[421],"Which of the following statements are true about starch?",[423,424,425],"Energy storage form in plants","Found in potatoes, rice, and corn","Broken down into glucose when consumed",[427,428,429],"Energy storage form in animals","Found in meat","Not broken down into glucose",{"id":431,"data":432,"type":53,"version":35,"maxContentLevel":19},"f398ce8d-4d21-468c-9ff4-cf2214f3b335",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":433,"multiChoiceCorrect":435,"multiChoiceIncorrect":439,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[434],"Which of the following statements are true about glycogen?",[436,437,438],"Energy storage form in animals and humans","Stored primarily in the liver and muscles","Broken down into glucose when energy is needed",[423,440,429],"Stored in the blood",{"id":442,"data":443,"type":35,"maxContentLevel":19,"version":35,"reviews":446},"8787d288-efea-4b82-8e77-04ada618caee",{"type":35,"markdownContent":444,"audioMediaId":445},"In addition to energy storage, carbohydrates provide structural support, which is closely related to the growth and development of living organisms.\n\nFor example, as we saw in the previous orb on carbon, **cellulose** is a carbohydrate that makes up the cell walls of plants. It gives plants their rigidity and strength, allowing them to stand upright and grow.\n\nAlthough humans cannot digest cellulose, it is an important part of our diet as dietary fiber, which helps maintain a healthy digestive system by promoting regular bowel movements and preventing constipation.\n\n![Graph](image://6813c562-6301-4230-b328-cc0e3399dade \"The outer husks of corn, primarily made from cellulose, cannot be digested by humans. Starr-160707-0054-Zea mays-Hawaiian Supersweet hybrid ears harvested-Hawea Pl Olinda-Maui (29632280186) by Forest and Kim Starr (CC BY 3.0 us) \u003Chttps://creativecommons.org/licenses/by/3.0/us/deed.en>, via Wikimedia Commons\")","d7715bea-8c74-470c-885f-5e96da2f9aad",[447],{"id":151,"data":448,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":449,"multiChoiceQuestion":450,"multiChoiceCorrect":452,"multiChoiceIncorrect":454,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":458,"matchPairsPairs":459},[152,153,148],[451],"What is the role of dietary fiber in humans?",[453],"Promotes regular bowel movements",[455,456,457],"Provides immediate energy","Forms cell walls","Acts as an enzyme",[95],[460],{"left":461,"right":453,"direction":19},"Dietary Fiber",{"id":463,"data":464,"type":35,"maxContentLevel":19,"version":19,"reviews":467},"9f762ea6-4ddf-497f-8af9-7c6025f553f2",{"type":35,"markdownContent":465,"audioMediaId":466},"Carbohydrates also play a role in **cell recognition and communication**.\n\nOn the surface of cells, carbohydrates are often attached to proteins and lipids, forming structures known as **glycoproteins** and **glycolipids**.\n\n![Graph](image://c5c55821-1ad8-4459-a0da-3731b4fcf04c \"A cell membrane with glycoproteins and glycolipids attatched. Image: OpenStax, CC BY 4.0 \u003Chttps://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons\")\n\nThese structures help cells recognize and interact with each other, which is important for the immune system and other cellular processes.\n\nFor instance, they help the immune system distinguish between the body's own cells and foreign invaders, such as bacteria and viruses.","0892db10-7bb9-4252-b592-2217b7891782",[468,480],{"id":469,"data":470,"type":53,"version":19,"maxContentLevel":19},"cd2eac9e-83fd-4500-b18b-96572946deec",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":471,"multiChoiceCorrect":473,"multiChoiceIncorrect":477,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[472],"Which of the below are the primary functions of complex carbohydrates?",[474,475,476],"Serve as energy storage molecules","Structural support in plants","Role in cell recognition and communication",[478,479,259],"Provide immediate energy","Transport of substancies",{"id":481,"data":482,"type":53,"version":35,"maxContentLevel":19},"5ec63d50-c10d-4aed-b4a1-4591ba2f223c",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":483,"multiChoiceCorrect":485,"multiChoiceIncorrect":488,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[484],"On the surface of cells, carbohydrates are often attached to proteins and lipids, forming new structures. What are these structures called, and what is their primary function?",[486,487],"Glycoproteins and glycolipids","Communication fuction: they help cells recognize and interact with each other",[489,490,491,492],"Proteolipids and liposaccharides","Structural function: they provide structural support to the cell membrane","Lipoglycans and protein sugars","Energy storage function: they store energy for the cell to use later",{"id":494,"data":495,"type":25,"version":35,"maxContentLevel":19,"summaryPage":497,"introPage":505,"pages":511},"a6c82aec-257a-403f-aa94-1952e7d670e7",{"type":25,"title":496},"Nucleic Acids",{"id":498,"data":499,"type":19,"maxContentLevel":19,"version":35},"f5c6fc31-3d5e-44a7-bd7e-5804299843e8",{"type":19,"summary":500},[501,502,503,504],"Nucleic acids are chains of smaller units that carry genetic information.","The phosphate group gives them their acidic nature.","The sequence of nitrogen-containing bases in these molecules encodes the instructions for building and running living cells.","Different forms of RNA play specialized roles in translating these instructions into the structure of proteins.",{"id":506,"data":507,"type":39,"maxContentLevel":19,"version":35},"654af494-5391-40d7-9ab2-84120d512837",{"type":39,"intro":508},[509,510],"What makes DNA's structure stable for storing genetic info?","How does mRNA help in protein production?",[512,551,568,587],{"id":513,"data":514,"type":35,"maxContentLevel":19,"version":35,"reviews":517},"3911e332-01ce-4da1-bc34-13138c2d4dbc",{"type":35,"markdownContent":515,"audioMediaId":516},"**Nucleic acids** are essential molecules in all living things because they store and pass on genetic information, guiding how cells function and reproduce.\n\nThe two main types of nucleic acids are **DNA** (deoxyribonucleic acid) and **RNA** (ribonucleic acid).\n\nThe \"**acid**\" in nucleic acids comes from the phosphate group, which can **lose a hydrogen ion**, leaving it with a negative charge.\n\nThis negative charge gives the molecule its acidic properties and allows it to interact with water and other charged molecules in the cell.\n\nThis interaction is important for the nucleic acid's ability to dissolve in water and function properly in the cell.","6e610a4c-07b1-4f32-9e85-dc8d684ea0b6",[518,528,544],{"id":519,"data":520,"type":53,"version":35,"maxContentLevel":19},"05db777a-bc75-4bf5-86b6-2380ce61a662",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":521,"multiChoiceCorrect":523,"multiChoiceIncorrect":525,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[522],"What are the two primary types of nucleic acids?",[524],"DNA and RNA",[526,527],"DNA and ATP","RNA and ATP",{"id":85,"data":529,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":530,"multiChoiceQuestion":531,"multiChoiceCorrect":533,"multiChoiceIncorrect":535,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":539,"matchPairsPairs":540},[80,83,84],[532],"What gives nucleic acids their acidic properties?",[534],"Phosphate group",[536,537,538],"Nitrogenous bases","Sugar group","Hydrogen bonds",[95],[541],{"left":542,"right":543,"direction":19},"Phosphate Group","Gives nucleic acid its acidic properties",{"id":545,"data":546,"type":53,"version":35,"maxContentLevel":19},"8f5a245a-1bb7-4dfe-aaf1-7d14b7c99dec",{"type":53,"reviewType":35,"spacingBehaviour":35,"activeRecallQuestion":547,"activeRecallAnswers":549},[548],"What does the acidic property of nucleic acid allow its molecules to do?",[550],"Gives it a negative charge, enabling interaction with water and other charged molecules in the cell",{"id":552,"data":553,"type":35,"maxContentLevel":19,"version":35,"reviews":556},"049e6906-ebb6-4e7a-b4d4-7a9180dbecaa",{"type":35,"markdownContent":554,"audioMediaId":555},"Nucleic acids are made up of smaller units called **nucleotides**. Each nucleotide has three parts: a sugar, a phosphate group, and a nitrogenous base.\n\n![Graph](image://9a072f60-44be-475e-aeb5-77e9856af9d6 \"The structure of nucleotides. Image: OpenStax College, CC BY 3.0 \u003Chttps://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons\")\n\nDNA is structured like a twisted ladder, known as a **double helix**. The sugar and phosphate groups form the sides of the ladder, creating a long chain, while the nitrogenous bases form the rungs.\n\nThe term \"nitrogenous\" refers to the fact that these bases (the rungs on the ladder) contain nitrogen atoms.","222c5ffe-eaec-4711-8490-40833f01df94",[557],{"id":558,"data":559,"type":53,"version":35,"maxContentLevel":19},"35fc501a-837e-4b46-bcd1-fdb0325e5ddb",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":560,"multiChoiceCorrect":562,"multiChoiceIncorrect":565,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[561],"What are the components of a nucleotide?",[563,534,564],"Sugar","Nitrogenous base",[566,567],"Lipid","Amino acid",{"id":569,"data":570,"type":35,"maxContentLevel":19,"version":35,"reviews":573},"acbbfa28-a77b-47ed-b72c-9e357eeb1a5e",{"type":35,"markdownContent":571,"audioMediaId":572},"The nitrogenous bases are the key to the genetic code because they pair up in specific ways to store information. In **DNA**, the bases are adenine (A), thymine (T), cytosine (C), and guanine (G).\n\nIn **RNA**, thymine is replaced by uracil (U).\n\n![Graph](image://af888ad4-ae4a-4b1b-8695-4d8b9bd5bbc5 \"The nitrogenous base pairings. Image: Sponk, CC BY-SA 3.0 \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")\n\nIn the ladder structure of DNA, adenine pairs with thymine, and cytosine pairs with guanine.\n\nThis stable structure allows DNA to securely store genetic information. When needed, the two strands of the DNA can separate to allow the information to be copied or used to make proteins.\n\n![Graph](image://34c2582c-7f75-4296-883a-110341ab3d2b \"Nucleic acids - Transcription by Laboratoires Servier (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")","0f9a24e0-3dd3-44f5-b043-db7fe120d748",[574],{"id":575,"data":576,"type":53,"version":35,"maxContentLevel":19},"523e6f2e-df3f-45d1-96eb-01033fa98dc1",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":577,"multiChoiceCorrect":579,"multiChoiceIncorrect":584,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[578],"Which bases are found in DNA?",[580,581,582,583],"Adenine","Thymine","Cytosine","Guanine",[585,586],"Uracil","Lysine",{"id":588,"data":589,"type":35,"maxContentLevel":19,"version":35,"reviews":592},"ba455abd-5665-4a7a-91a3-b883f3731c31",{"type":35,"markdownContent":590,"audioMediaId":591},"**RNA**, on the other hand, is usually single-stranded and more flexible. Because of this flexibility, RNA can fold into various shapes, enabling it to perform different functions within the cell.\n\nThere are three main types of RNA, each with a specific role:\n\n**Messenger RNA** (mRNA): mRNA carries genetic instructions from DNA to the ribosomes, where proteins are synthesized. It acts as a template for assembling amino acids in the correct order to produce a specific protein.\n\n**Ribosomal RNA** (rRNA): rRNA is a key component of ribosomes, the cellular structures where proteins are made. rRNA helps to align the mRNA and the ribosomes and catalyzes the formation of the bonds between amino acids.\n\n**Transfer RNA** (tRNA): tRNA transports amino acids to the ribosome during protein synthesis. Each tRNA molecule recognizes specific sequences of mRNA and ensures that the correct amino acid is added to the growing protein chain.","dc1f3eb8-52a4-4c0f-a403-e001fa65f6dc",[593,604,616],{"id":594,"data":595,"type":53,"version":35,"maxContentLevel":19},"b2de381e-7a29-48e4-9699-7e5a8194e82c",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":596,"multiChoiceCorrect":598,"multiChoiceIncorrect":600,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[597],"How is RNA usually structured?",[599],"Single-stranded",[601,602,603],"Double-stranded","Triple-stranded","Circular form",{"id":605,"data":606,"type":53,"version":35,"maxContentLevel":19},"557eb080-1616-4d4c-ad56-06c74bbf9f69",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":607,"multiChoiceCorrect":609,"multiChoiceIncorrect":613,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[608],"Which of the below are the main types of RNA?",[610,611,612],"mRNA","rRNA","tRNA",[614,615],"dRNA","bRNA",{"id":617,"data":618,"type":53,"version":35,"maxContentLevel":19},"3c266f46-6689-49a2-9e21-36fe740b3261",{"type":53,"reviewType":269,"spacingBehaviour":35,"matchPairsQuestion":619,"matchPairsPairs":621,"matchPairsShowExamples":6},[620],"Match the pair below:",[622,625,628,631],{"left":623,"right":624,"direction":19},"Messenger RNA (mRNA)","Template for assembling amino acids",{"left":626,"right":627,"direction":19},"Ribosomal RNA (rRNA)","Aligns mRNA and ribosomes",{"left":629,"right":630,"direction":19},"Transfer RNA (tRNA)","Transports amino acids to ribosome",{"left":632,"right":633,"direction":19},"Ribosome","Cellular structure where proteins are made",{"id":635,"data":636,"type":25,"version":25,"maxContentLevel":19,"summaryPage":638,"introPage":646,"pages":652},"774797b5-0925-4fc4-979d-11c4730e5473",{"type":25,"title":637},"Water",{"id":639,"data":640,"type":19,"maxContentLevel":19,"version":35},"e6c01c1b-b4e5-4186-b040-e12750c346ff",{"type":19,"summary":641},[642,643,644,645],"Water's polarity makes it a great solvent for substances.","High specific heat stabilizes temperatures in organisms and environments.","Cohesion and adhesion enable water movement in plants.","Water buffers pH, crucial for enzyme function.",{"id":647,"data":648,"type":39,"maxContentLevel":19,"version":35},"66a33b29-13f9-49f7-b083-05d149685f63",{"type":39,"intro":649},[650,651],"What makes water such a great solvent?","How does water help plants get nutrients?",[653,692,736],{"id":654,"data":655,"type":35,"maxContentLevel":19,"version":35,"reviews":658},"bebf057e-c813-404a-a719-d47e104c46b1",{"type":35,"markdownContent":656,"audioMediaId":657},"We’re going to briefly move away from the organic molecules crucial to life to examine a fundamental molecule that will enhance your understanding of later sections, such as lipids. This molecule is **water**.\n\nWater is essential for life due to its unique properties that directly support living organisms.\n\nOne of the key characteristics of water is its **polarity**. A water molecule is made up of one oxygen atom and two hydrogen atoms. These atoms share electrons, but not equally, which gives the oxygen side of the molecule a slight negative charge and the hydrogen side a slight positive charge.\n\n![Graph](image://befaa48c-afa2-4395-8210-44bd7f4356a7 \"Water molecule. The oxygen side of the molecule a slight negative charge and the hydrogen side a slight positive charge. Image: Riccardo Rovinetti, CC BY-SA 3.0 \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons\")\n\nThis makes water a **polar molecule**, meaning it has a positive and a negative side, similar to a magnet.\n\nBecause of its polarity, water can form hydrogen bonds with other water molecules and with other polar substances. These bonds are weak attractions that allow water to dissolve many substances, making it an excellent solvent.\n\nFor example, when salt is added to water, the water molecules surround and separate the salt's ions, causing the salt to dissolve.\n\nThis ability to dissolve substances is crucial for transporting nutrients and removing waste in living organisms, ensuring that cells get the materials they need to function and stay healthy.","5112ffe4-7266-4754-a9ce-4af64d79d298",[659,679],{"id":660,"data":661,"type":53,"version":35,"maxContentLevel":19},"12fb5a35-56f9-403d-9f4e-8c459cbc241e",{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":662,"multiChoiceQuestion":666,"multiChoiceCorrect":668,"multiChoiceIncorrect":670,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":674,"matchPairsPairs":675},[663,664,665],"9b4d45ad-9235-493e-a258-6c79d96a6c42","11e8096f-c6ff-471e-b2fd-a9262d58cd0c","6913c49b-ce43-4e15-b77a-1fb70d1f182f",[667],"What enables water to dissolve many substances?",[669],"Hydrogen Bonds",[671,672,673],"Cohesion","Adhesion","Capillary Action",[95],[676],{"left":677,"right":678,"direction":19},"Hydrogen bonding between polar molecules","Enables water to dissolve many substances",{"id":680,"data":681,"type":53,"version":35,"maxContentLevel":19},"4ac07d8b-e5fa-4da3-8513-442fa1ff5f1a",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":682,"multiChoiceCorrect":684,"multiChoiceIncorrect":688,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[683],"Which of the following are true about a water molecule?",[685,686,687],"Made up of one oxygen atom and two hydrogen atoms","Has a slight negative charge on oxygen side","Has a slight positive charge on hydrogen side",[689,690,691],"Made up of two oxygen atom and one hydrogen atoms","Has a slight positive charge on oxygen side","Has a slight negative charge on hydrogen side",{"id":693,"data":694,"type":35,"maxContentLevel":19,"version":25,"reviews":697},"896b309f-6da9-4663-949f-d5f60214ce1f",{"type":35,"markdownContent":695,"audioMediaId":696},"Water also has a **high specific heat capacity**, meaning it can absorb a lot of heat before its temperature increases. This property helps stabilize temperatures in organisms and their environments.\n\nFor instance, the large amounts of water in the human body **help maintain a stable internal temperature**, which is vital for enzymes and metabolic processes to function properly.\n\nAnother important feature of water is its **cohesion** and **adhesion**.\n\n**Cohesion** is the ability of water molecules to stick to *other water molecules*, which creates **surface tension**.\n\nThis property is illustrated by the way small insects, like water striders, can walk on water without sinking. In living organisms, this surface tension is important for processes like the movement of water in plants.\n\n![Graph](image://2380ba8e-060d-4eae-b839-83d154344d85 \"Gerridae on a lake. Image by Olexandr Ostrovyi (CC BY 4.0) \u003Chttps://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons\")\n\n**Adhesion**, on the other hand, is water's ability to stick to *different* substances, which, along with cohesion, enables capillary action. In plants, capillary action helps water travel from the roots to the leaves, which is essential for transporting nutrients and maintaining plant health.\n\n![Graph](image://cd79fda1-0cfd-4c13-ac9e-5be40ff79298 \"Mangrove plant roots provides an island in the water (Public domain), via Wikimedia Commons\")","8b4afe1d-2789-411a-b8bd-6b6bf741e198",[698,712,727],{"id":663,"data":699,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":700,"multiChoiceQuestion":701,"multiChoiceCorrect":703,"multiChoiceIncorrect":705,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":707,"matchPairsPairs":708},[660,664,665],[702],"What property of water helps stabilize temperatures in organisms and their environments?",[704],"High heat capacity",[706,671,672],"Polarity",[95],[709],{"left":710,"right":711,"direction":19},"High Heat Capacity","Enables water to stabilize temperatures in organisms and their environments",{"id":665,"data":713,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":714,"multiChoiceQuestion":715,"multiChoiceCorrect":717,"multiChoiceIncorrect":719,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":723,"matchPairsPairs":724},[660,663,664],[716],"What do the cohesive and adhesive properties of water enable in plants?",[718],"Water travelling from roots to leaves (capillary action)",[720,721,722],"Regulation of leaf temperature (temperature regulation)","Formation of protective waxy coatings on leaves","Maintenance of plant rigidity",[95],[725],{"left":671,"right":726,"direction":19},"Along with adhesion, enables capillary action in plants",{"id":728,"data":729,"type":53,"version":25,"maxContentLevel":19},"41125665-e2d1-4fca-b756-7471a95f8a2c",{"type":53,"reviewType":269,"spacingBehaviour":35,"matchPairsQuestion":730,"matchPairsPairs":731,"matchPairsShowExamples":6},[95],[732,734],{"left":672,"right":733,"direction":19},"Water molecules' ability  to stick to other substances",{"left":671,"right":735,"direction":19},"Water molecules' ability stick to each other",{"id":737,"data":738,"type":35,"maxContentLevel":19,"version":35,"reviews":741},"d420aee9-04e9-4a6a-8325-a9aae6dfc70f",{"type":35,"markdownContent":739,"audioMediaId":740},"Finally, water helps **maintain pH balance** in living organisms. pH measures how acidic or basic a solution is, and maintaining a stable pH is crucial for life.\n\n![Graph](image://bfddb423-7b46-47f6-b6bb-a7dd047d8370 \"216 pH Scale-01 by OpenStax College (CC BY 3.0) \u003Chttps://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons\")\n\nWater acts as a **buffer**, absorbing excess hydrogen or hydroxide ions by surrounding them with water molecules, which helps to keep pH levels stable.\n\nThis is important for maintaining the proper conditions for enzymes and other proteins to function, such as in human blood, where a stable pH of around 7.4 is necessary for the body to function effectively.","37cfe8e6-64ea-45d5-bc5e-4600f738d189",[742,757],{"id":664,"data":743,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":744,"multiChoiceQuestion":745,"multiChoiceCorrect":747,"multiChoiceIncorrect":749,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":752,"matchPairsPairs":753},[660,663,665],[746],"What is the consequence of water's buffering capacity?",[748],"Maintains pH balance",[750,678,751],"Creates surface tension","Can absorb a lot of heat before temperature increases",[95],[754],{"left":755,"right":756,"direction":19},"Buffering Capacity","Results in water's ability to maintain pH balance",{"id":83,"data":758,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":759,"multiChoiceQuestion":760,"multiChoiceCorrect":762,"multiChoiceIncorrect":764,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":768,"matchPairsPairs":769},[80,84,85],[761],"Why does salt dissolve in water?",[763],"Due to water's polarity",[765,766,767],"Due to water's cohesion","Due to water's adhesion","Due to water's buffering capacity",[95],[770],{"left":771,"right":772,"direction":19},"Salt","Dissolves in water due to water's polarity",{"id":774,"data":775,"type":25,"version":19,"maxContentLevel":19,"summaryPage":777,"introPage":785,"pages":791},"05f9985f-aa29-42b7-b552-8b67e23db47e",{"type":25,"title":776},"Lipids",{"id":778,"data":779,"type":19,"maxContentLevel":19,"version":35},"ef7c6279-bc36-4695-9622-82aeae09c6b2",{"type":19,"summary":780},[781,782,783,784],"Lipids store energy as fats with glycerol and fatty acids.","Phospholipids form cell membranes with hydrophilic heads and tails.","Steroids stabilize cell membranes and act as signaling molecules.","Lipids help cells communicate by influencing gene expression.",{"id":786,"data":787,"type":39,"maxContentLevel":19,"version":35},"b12dffbb-5643-41aa-90b1-11671cda8af7",{"type":39,"intro":788},[789,790],"How do lipids store energy in the body?","What role do phospholipids play in cell membranes?",[792,839,893,921],{"id":793,"data":794,"type":35,"maxContentLevel":19,"version":35,"reviews":797},"eb1395ed-33af-4507-b3a4-b7ce4245bc24",{"type":35,"markdownContent":795,"audioMediaId":796},"**Lipids** are a group of molecules that don't mix well with water, making them essential for many biological functions.\n\nThese molecules are mainly made up of hydrogen and carbon atoms.\n\nBecause of this composition, lipids are **nonpolar**, meaning they don't have a positive or negative charge that would allow them to interact with water molecules.\n\nWater is polar, which means it has regions of slight positive and negative charge, allowing water molecules to stick together.\n\nSince lipids are nonpolar, they don't interact well with water and, therefore, do not dissolve in it. Instead, they separate from water, similar to how oil separates from water in a mixture.\n\n![Graph](image://c43a6f4d-57b1-4fff-9d2d-477fdf7624c0 \"Oil separating from water. Image by Roger McLassus 1951 (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons\")\n\nThis property is what makes lipids useful for **forming barriers**, such as **cell membranes**, and storing energy in the body.\n\nBesides storing energy and forming membranes, lipids also **insulate and protect**. For example, a layer of fat beneath the skin helps animals maintain their body temperature by reducing heat loss.\n\nAdditionally, lipids cushion organs, providing a protective layer that absorbs shock.","a94766fb-4d2e-4ae2-b1c4-5ded3975fb00",[798,813,828],{"id":84,"data":799,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":800,"multiChoiceQuestion":801,"multiChoiceCorrect":803,"multiChoiceIncorrect":805,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":809,"matchPairsPairs":810},[80,83,85],[802],"What is the definition of lipids?",[804],"Group of molecules that don't mix well with water (nonpolar)",[806,807,808],"Group of molecules that mix well with water","Group of molecules that are polar","Group of molecules that are hydrophilic",[95],[811],{"left":776,"right":812,"direction":19},"Do not mix well with water (nonpolar)",{"id":194,"data":814,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":815,"multiChoiceQuestion":816,"multiChoiceCorrect":818,"multiChoiceIncorrect":820,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":824,"matchPairsPairs":825},[191,195],[817],"What are lipids mainly made up of?",[819],"Hydrogen and carbon atoms",[821,822,823],"Oxygen and nitrogen atoms","Carbon and nitrogen atoms","Hydrogen and oxygen atoms",[95],[826],{"left":776,"right":827,"direction":19},"Mainly made up of hydrogen and carbon atoms",{"id":829,"data":830,"type":53,"version":35,"maxContentLevel":19},"7833a032-b092-4e13-90a6-571bc83f2e81",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":831,"multiChoiceCorrect":833,"multiChoiceIncorrect":835,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[832],"What are lipids useful for?",[834],"Forming barriers and storing energy",[836,837,838],"Forming proteins","Transportation","Working as enzymes",{"id":840,"data":841,"type":35,"maxContentLevel":19,"version":35,"reviews":844},"38e22e34-e8d5-4afe-95b2-4782bab14e3a",{"type":35,"markdownContent":842,"audioMediaId":843},"The main types of lipids include: **fats**, **oils**, **waxes**, **phospholipids**, and **steroids**, each with its own important role in living organisms.\n\nOne key function of lipids is **storing energy**.\n\nFats, also called **triglycerides**, are the primary way animals store energy.\n\nA fat molecule consists of a glycerol backbone connected to **three fatty acid chains**. These **fatty acids** can be either saturated or unsaturated.\n\n![Graph](image://24c88545-a002-4e00-8516-248106858c5a \"Butter and Oil - NCI Visuals Online (Public domain), via Wikimedia Commons\")\n\n**Saturated fatty acids** have no double bonds between the carbon atoms, so they are fully saturated with hydrogen atoms. This makes them straight, allowing them to pack tightly together, which is why saturated fats are usually solid at room temperature, like butter.\n\n**Unsaturated fatty acids**, on the other hand, have one or more double bonds, creating bends in the chain that prevent tight packing, making them liquid at room temperature, like olive oil.","38d2f168-b55f-4cbe-ab3f-afe8ef7dc9ef",[845,858,873,880],{"id":846,"data":847,"type":53,"version":35,"maxContentLevel":19},"cac170ca-787a-4cde-96d8-a707a71a94eb",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":848,"multiChoiceCorrect":850,"multiChoiceIncorrect":855,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[849],"Which of the following are examples of lipids?",[851,852,853,854],"Fats","Oils","Waxes","Steroids",[856,349,857],"Amino acids","Nucleic acids",{"id":152,"data":859,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":860,"multiChoiceQuestion":861,"multiChoiceCorrect":863,"multiChoiceIncorrect":865,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":869,"matchPairsPairs":870},[151,153,148],[862],"What is the primary way animals store energy?",[864],"Fats (Triglycerides)",[866,867,868],"Proteins (Polypeptides)","Carbohydrates (Polysaccharides)","Nucleic acids (DNA/RNA)",[95],[871],{"left":864,"right":872,"direction":19},"Primary way animals store energy",{"id":874,"data":875,"type":53,"version":35,"maxContentLevel":19},"eac76435-6333-4a0d-96be-222960f7b38a",{"type":53,"reviewType":20,"spacingBehaviour":35,"clozeQuestion":876,"clozeWords":878},[877],"Fat modules contain glycerol and 3 fatty acid chains that can be either saturated or unsaturated.",[879],"3 fatty acid chains",{"id":881,"data":882,"type":53,"version":35,"maxContentLevel":19},"3c12d661-62e6-420e-afe5-9b84c0a9fd5a",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":883,"multiChoiceCorrect":885,"multiChoiceIncorrect":889,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[884],"Which of the following are characteristics of unsaturated fatty acids?",[886,887,888],"One or more double bonds","Bends in the chain, prevent tight packing","Liquid at room temperature",[890,891,892],"No double bonds","Fully saturated with hydrogen atoms","Solid at room temperature",{"id":894,"data":895,"type":35,"maxContentLevel":19,"version":19,"reviews":898},"b8ea73c1-bee8-4a21-b330-d0e1bd386606",{"type":35,"markdownContent":896,"audioMediaId":897},"Phospholipids are another important type of lipid, especially for **forming cell membranes.**\n\nA phospholipid molecule has a glycerol backbone, two fatty acid tails, and a phosphate group.\n\nThe phosphate group is **hydrophilic**, meaning it attracts water, while the fatty acid tails are **hydrophobic**, meaning they repel water.\n\nThis unique structure allows phospholipids to form double layers in water, with the fatty acid tails facing inward and the heads facing outward.\n\n![Graph](image://d96b1f4c-9f72-4c03-abcd-677ebc6d3bf0 \"Phospholipid structure of a cell membrane. Image: TvanBrussel (Copyrighted free use), via Wikimedia Commons\")\n\nThis arrangement **creates the cell membrane**, a barrier that controls what enters and leaves the cell.","715e5f37-7909-41a5-9dbf-8c93fe9022c0",[899,910],{"id":900,"data":901,"type":53,"version":19,"maxContentLevel":19},"e00f1e7f-036b-453b-a8c4-159c35d4a8d9",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":902,"multiChoiceCorrect":904,"multiChoiceIncorrect":907,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[903],"Which two of the following statements about the components of phospholipids are true, allowing phospholipids to form double layers in water?",[905,906],"The phosphate group is hydrophilic, attracting water","The two fatty acid tails are hydrophobic, repelling water",[908,909],"The two fatty acid tails are hydrophilic, attracting water","The phosphate group is hydrophobic, repelling water",{"id":911,"data":912,"type":53,"version":35,"maxContentLevel":19},"0b42429e-a635-4c4c-bc9e-1c340901b985",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":913,"multiChoiceCorrect":915,"multiChoiceIncorrect":917,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6},[914],"Phospholipids form double layers in water. What part of the cell is made of this structure?",[916],"The cell membrane",[918,919,920],"The nucleus","The nuclear envelope","Produces hormones",{"id":922,"data":923,"type":35,"maxContentLevel":19,"version":35,"reviews":926},"56eb6f9f-31c6-4815-ad56-32ecd3c85118",{"type":35,"markdownContent":924,"audioMediaId":925},"**Steroids** are a different kind of lipid with a structure made up of four connected carbon rings.\n\nCholesterol is a well-known steroid that is crucial for cell membrane stability and fluidity.\n\nCholesterol also serves as a building block for **steroid hormones** like **testosterone** and **estrogen**, which regulate many body functions.\n\nAdditionally, **cholesterol** is necessary for producing bile salts that help digest and absorb fats from food.\n\nLipids such as steroids also play a role in **communication between cells**. Some lipids act as signaling molecules, influencing how cells behave.\n\nFor example, steroid hormones derived from cholesterol can enter cells and bind to receptors, causing changes in how genes are expressed and how the cell functions.\n\nThis ability to signal is vital for maintaining balance in the body and coordinating complex biological responses.","c7e98dfd-73dd-471a-bca3-cf9f8a19ab3d",[927,941,956,969],{"id":195,"data":928,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":929,"multiChoiceQuestion":930,"multiChoiceCorrect":932,"multiChoiceIncorrect":934,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":938,"matchPairsPairs":939},[191,194],[931],"What is the structure of steroids?",[933],"Made up of four connected carbon rings",[935,936,937],"Made up of three connected carbon rings","Made up of five connected carbon rings","Made up of two connected carbon rings",[95],[940],{"left":854,"right":933,"direction":19},{"id":212,"data":942,"type":53,"version":35,"maxContentLevel":19},{"type":53,"reviewType":19,"spacingBehaviour":35,"collapsingSiblings":943,"multiChoiceQuestion":944,"multiChoiceCorrect":946,"multiChoiceIncorrect":948,"multiChoiceMultiSelect":6,"multiChoiceRevealAnswerOption":6,"matchPairsQuestion":952,"matchPairsPairs":953},[211,208,213],[945],"What role do steroids play in cells?",[947],"Cell communication",[949,950,951],"Energy storage","Protein synthesis","Carbohydrate metabolism",[95],[954],{"left":854,"right":955,"direction":19},"Play a role in cell communication",{"id":957,"data":958,"type":53,"version":35,"maxContentLevel":19},"2ac3e2c8-dc9e-4c21-a408-e7d85f58788f",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":959,"multiChoiceCorrect":961,"multiChoiceIncorrect":965,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[960],"Which of the following are examples of steroids?",[962,963,964],"Cholesterol","Testosterone","Estrogen",[966,967,968,312],"Glycerol","Phosphate","Triglycerides",{"id":970,"data":971,"type":53,"version":35,"maxContentLevel":19},"8b0b17ff-8503-4e5c-be72-d15b1a1492c8",{"type":53,"reviewType":19,"spacingBehaviour":35,"multiChoiceQuestion":972,"multiChoiceCorrect":974,"multiChoiceIncorrect":978,"multiChoiceMultiSelect":127,"multiChoiceRevealAnswerOption":6},[973],"Which of the following are functions of cholesterol?",[975,976,977],"Building block for steroid hormones","Necessary for producing bile salts","Stabilizes cell membrane",[979,950,951],"Primary energy storage",[981,1347,1579,1823,2043,2270],{"id":23,"data":24,"type":25,"version":25,"maxContentLevel":19,"summaryPage":27,"introPage":36,"pages":982},[983,1051,1146,1237],{"id":45,"data":46,"type":35,"maxContentLevel":19,"version":35,"reviews":49,"parsed":984},{"data":985,"body":988,"toc":1049},{"title":986,"description":987},"","All life on Earth is composed of chemicals arranged in specific structures. While the periodic table includes many elements, only a particular subset—like carbon, hydrogen, oxygen, and nitrogen—plays a central role in the chemistry of life, forming stable and complex molecules that are essential for biological processes.",{"type":989,"children":990},"root",[991,998,1011,1021,1033,1038],{"type":992,"tag":993,"props":994,"children":995},"element","p",{},[996],{"type":997,"value":987},"text",{"type":992,"tag":993,"props":999,"children":1000},{},[1001,1003,1009],{"type":997,"value":1002},"This tile will track through the chemical compositions that make up living organisms, starting with perhaps the most important of all: ",{"type":992,"tag":1004,"props":1005,"children":1006},"strong",{},[1007],{"type":997,"value":1008},"carbon",{"type":997,"value":1010},".",{"type":992,"tag":993,"props":1012,"children":1013},{},[1014],{"type":992,"tag":1015,"props":1016,"children":1020},"img",{"alt":1017,"src":1018,"title":1019},"Graph","image://e6cfe26e-c0ba-4299-b113-a72a11f23a2b","Graphene. Image by AlexanderAlUS (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1022,"children":1023},{},[1024,1026,1031],{"type":997,"value":1025},"The image above is a graphical representation of a kind of structure known as ",{"type":992,"tag":1004,"props":1027,"children":1028},{},[1029],{"type":997,"value":1030},"graphene",{"type":997,"value":1032},", an extraordinary material made of a single layer of carbon atoms. The carbon atoms are arranged in a hexagonal lattice, resembling a honeycomb.",{"type":992,"tag":993,"props":1034,"children":1035},{},[1036],{"type":997,"value":1037},"Despite being only one atom thick, graphene is incredibly strong, lightweight, and highly conductive, and these days it is being used in cutting-edge technologies, such as nanoscale machines, ultra-sensitive sensors, and advanced electronic devices.",{"type":992,"tag":993,"props":1039,"children":1040},{},[1041,1043,1047],{"type":997,"value":1042},"But long before these technologies, nature used the unique properties of ",{"type":992,"tag":1004,"props":1044,"children":1045},{},[1046],{"type":997,"value":1008},{"type":997,"value":1048}," to build life.",{"title":986,"searchDepth":25,"depth":25,"links":1050},[],{"id":63,"data":64,"type":35,"maxContentLevel":19,"version":25,"reviews":67,"parsed":1052},{"data":1053,"body":1055,"toc":1144},{"title":986,"description":1054},"Carbon is a fundamental element in the chemistry of life, acting as the backbone for a wide variety of biological molecules.",{"type":989,"children":1056},[1057,1061,1069,1107,1119,1131,1139],{"type":992,"tag":993,"props":1058,"children":1059},{},[1060],{"type":997,"value":1054},{"type":992,"tag":993,"props":1062,"children":1063},{},[1064],{"type":992,"tag":1015,"props":1065,"children":1068},{"alt":1017,"src":1066,"title":1067},"image://b5c00ee2-9660-407a-b681-9d447fe8a8aa","Pure Carbon by Texas Lane (CC BY-SA 4.0) \u003Chttps://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1070,"children":1071},{},[1072,1074,1079,1081,1086,1088,1093,1094,1099,1101,1106],{"type":997,"value":1073},"This is because carbon has a unique ability to ",{"type":992,"tag":1004,"props":1075,"children":1076},{},[1077],{"type":997,"value":1078},"form stable bonds",{"type":997,"value":1080}," with many other elements, including with itself. This characteristic allows for the creation of complex molecules essential for life, such as ",{"type":992,"tag":1004,"props":1082,"children":1083},{},[1084],{"type":997,"value":1085},"proteins",{"type":997,"value":1087},", ",{"type":992,"tag":1004,"props":1089,"children":1090},{},[1091],{"type":997,"value":1092},"nucleic acids",{"type":997,"value":1087},{"type":992,"tag":1004,"props":1095,"children":1096},{},[1097],{"type":997,"value":1098},"carbohydrates",{"type":997,"value":1100},", and ",{"type":992,"tag":1004,"props":1102,"children":1103},{},[1104],{"type":997,"value":1105},"lipids",{"type":997,"value":1010},{"type":992,"tag":993,"props":1108,"children":1109},{},[1110,1112,1117],{"type":997,"value":1111},"Specifically, carbon atoms can form ",{"type":992,"tag":1004,"props":1113,"children":1114},{},[1115],{"type":997,"value":1116},"four covalent bonds",{"type":997,"value":1118}," with other atoms. This means that a single carbon atom can connect with up to four other atoms, creating a three-dimensional structure.",{"type":992,"tag":993,"props":1120,"children":1121},{},[1122,1124,1129],{"type":997,"value":1123},"For example, in a methane molecule (",{"type":992,"tag":1004,"props":1125,"children":1126},{},[1127],{"type":997,"value":1128},"CH4",{"type":997,"value":1130},"), carbon forms four bonds with hydrogen atoms, which gives the molecule a stable structure.",{"type":992,"tag":993,"props":1132,"children":1133},{},[1134],{"type":992,"tag":1015,"props":1135,"children":1138},{"alt":1017,"src":1136,"title":1137},"image://682cefc4-866c-4e4b-93d8-eac6b4cbb229","Methane (CH4). Image: DynaBlast, CC BY-SA 2.5 \u003Chttps://creativecommons.org/licenses/by-sa/2.5>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1140,"children":1141},{},[1142],{"type":997,"value":1143},"This ability to form multiple bonds makes carbon incredibly versatile, allowing it to be the foundation for large and complex molecules, known as macromolecules.",{"title":986,"searchDepth":25,"depth":25,"links":1145},[],{"id":101,"data":102,"type":35,"maxContentLevel":19,"version":35,"reviews":105,"parsed":1147},{"data":1148,"body":1150,"toc":1235},{"title":986,"description":1149},"Carbon's ability to form double and triple bonds with other carbon atoms adds another layer of diversity to molecules. These types of bonds change the shape and properties of the molecules. For example, double bonds make a molecule more rigid and less flexible, affecting how it behaves and reacts with other substances.",{"type":989,"children":1151},[1152,1156,1185,1197,1202,1230],{"type":992,"tag":993,"props":1153,"children":1154},{},[1155],{"type":997,"value":1149},{"type":992,"tag":993,"props":1157,"children":1158},{},[1159,1161,1166,1167,1172,1173,1178,1179,1184],{"type":997,"value":1160},"In addition to bonding with other carbon atoms, carbon can also form stable bonds with elements like ",{"type":992,"tag":1004,"props":1162,"children":1163},{},[1164],{"type":997,"value":1165},"oxygen",{"type":997,"value":1087},{"type":992,"tag":1004,"props":1168,"children":1169},{},[1170],{"type":997,"value":1171},"nitrogen",{"type":997,"value":1087},{"type":992,"tag":1004,"props":1174,"children":1175},{},[1176],{"type":997,"value":1177},"sulfur",{"type":997,"value":1100},{"type":992,"tag":1004,"props":1180,"children":1181},{},[1182],{"type":997,"value":1183},"phosphorus",{"type":997,"value":1010},{"type":992,"tag":993,"props":1186,"children":1187},{},[1188,1190,1195],{"type":997,"value":1189},"When carbon bonds with these elements, it creates ",{"type":992,"tag":1004,"props":1191,"children":1192},{},[1193],{"type":997,"value":1194},"functional groups",{"type":997,"value":1196},", which are specific clusters of atoms that give a molecule certain properties and make it behave in a predictable way.",{"type":992,"tag":993,"props":1198,"children":1199},{},[1200],{"type":997,"value":1201},"Functional groups are important because they determine how a molecule interacts in chemical reactions. For example:",{"type":992,"tag":1203,"props":1204,"children":1205},"ul",{},[1206,1219],{"type":992,"tag":1207,"props":1208,"children":1209},"li",{},[1210,1212,1217],{"type":997,"value":1211},"The ",{"type":992,"tag":1004,"props":1213,"children":1214},{},[1215],{"type":997,"value":1216},"hydroxyl group",{"type":997,"value":1218}," (–OH) makes a molecule more likely to dissolve in water.",{"type":992,"tag":1207,"props":1220,"children":1221},{},[1222,1223,1228],{"type":997,"value":1211},{"type":992,"tag":1004,"props":1224,"children":1225},{},[1226],{"type":997,"value":1227},"carboxyl group",{"type":997,"value":1229}," (–COOH) makes a molecule acidic, like in fatty acids.",{"type":992,"tag":993,"props":1231,"children":1232},{},[1233],{"type":997,"value":1234},"These functional groups are essential for processes in living organisms, such as metabolism, gene expression, and cell communication.",{"title":986,"searchDepth":25,"depth":25,"links":1236},[],{"id":129,"data":130,"type":35,"maxContentLevel":19,"version":35,"reviews":133,"parsed":1238},{"data":1239,"body":1241,"toc":1345},{"title":986,"description":1240},"Carbohydrates are a prime example of the complexity and diversity that carbon can create in biological systems.",{"type":989,"children":1242},[1243,1252,1260,1282,1292,1318,1337],{"type":992,"tag":993,"props":1244,"children":1245},{},[1246,1250],{"type":992,"tag":1004,"props":1247,"children":1248},{},[1249],{"type":997,"value":349},{"type":997,"value":1251}," are a prime example of the complexity and diversity that carbon can create in biological systems.",{"type":992,"tag":993,"props":1253,"children":1254},{},[1255],{"type":992,"tag":1015,"props":1256,"children":1259},{"alt":1017,"src":1257,"title":1258},"image://8799a3cf-65d4-4572-ba2d-a5210fb4132e","The chemical composition of glucose (a corbohydrate) made of carbon (C), oxygen (O) and hydrogen (H). Image: Ben; Yikrazuul, Public domain, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1261,"children":1262},{},[1263,1265,1269,1270,1275,1276,1280],{"type":997,"value":1264},"Carbohydrates are composed of ",{"type":992,"tag":1004,"props":1266,"children":1267},{},[1268],{"type":997,"value":1008},{"type":997,"value":1087},{"type":992,"tag":1004,"props":1271,"children":1272},{},[1273],{"type":997,"value":1274},"hydrogen",{"type":997,"value":1100},{"type":992,"tag":1004,"props":1277,"children":1278},{},[1279],{"type":997,"value":1165},{"type":997,"value":1281},", and they play crucial roles in energy storage, structural integrity, and cellular communication in living organisms.",{"type":992,"tag":993,"props":1283,"children":1284},{},[1285,1290],{"type":992,"tag":1004,"props":1286,"children":1287},{},[1288],{"type":997,"value":1289},"Simple carbohydrates",{"type":997,"value":1291},", like glucose, serve as a primary energy source for cells.",{"type":992,"tag":993,"props":1293,"children":1294},{},[1295,1297,1302,1304,1309,1311,1316],{"type":997,"value":1296},"When multiple glucose molecules bond together, they can form ",{"type":992,"tag":1004,"props":1298,"children":1299},{},[1300],{"type":997,"value":1301},"complex carbohydrates",{"type":997,"value":1303},", such as ",{"type":992,"tag":1004,"props":1305,"children":1306},{},[1307],{"type":997,"value":1308},"starch",{"type":997,"value":1310}," and ",{"type":992,"tag":1004,"props":1312,"children":1313},{},[1314],{"type":997,"value":1315},"cellulose",{"type":997,"value":1317},", which are essential for energy storage in plants and structural support in plant cell walls, respectively.",{"type":992,"tag":993,"props":1319,"children":1320},{},[1321,1323,1328,1330,1335],{"type":997,"value":1322},"Humans and other animals consume ",{"type":992,"tag":1004,"props":1324,"children":1325},{},[1326],{"type":997,"value":1327},"starchy plants",{"type":997,"value":1329},", like ",{"type":992,"tag":1004,"props":1331,"children":1332},{},[1333],{"type":997,"value":1334},"potatoes",{"type":997,"value":1336},", to access this stored energy, breaking down the starch into glucose for use in metabolic processes.",{"type":992,"tag":993,"props":1338,"children":1339},{},[1340],{"type":992,"tag":1015,"props":1341,"children":1344},{"alt":1017,"src":1342,"title":1343},"image://09526bc1-e406-46b1-a7ea-a0b332d8443b","Potato and cross section (GFDL 1.2) \u003Chttp://www.gnu.org/licenses/old-licenses/fdl-1.2.html>, via Wikimedia Commons",[],{"title":986,"searchDepth":25,"depth":25,"links":1346},[],{"id":165,"data":166,"type":25,"version":35,"maxContentLevel":19,"summaryPage":168,"introPage":177,"pages":1348},[1349,1401,1469,1535],{"id":185,"data":186,"type":35,"maxContentLevel":19,"version":35,"reviews":189,"parsed":1350},{"data":1351,"body":1353,"toc":1399},{"title":986,"description":1352},"Proteins are essential molecules that play a crucial role in the characteristics of life. They are made up of smaller units called amino acids, which are linked together in long chains.",{"type":989,"children":1354},[1355,1359,1367,1378,1383,1394],{"type":992,"tag":993,"props":1356,"children":1357},{},[1358],{"type":997,"value":1352},{"type":992,"tag":993,"props":1360,"children":1361},{},[1362],{"type":992,"tag":1015,"props":1363,"children":1366},{"alt":1017,"src":1364,"title":1365},"image://68d85488-06f0-4c92-8c50-c6985bf46ee3","A long protein chain (CC BY-SA 4.0) \u003Chttps://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1368,"children":1369},{},[1370,1371,1376],{"type":997,"value":1211},{"type":992,"tag":1004,"props":1372,"children":1373},{},[1374],{"type":997,"value":1375},"sequence",{"type":997,"value":1377}," of these amino acids determines the protein's shape and function.",{"type":992,"tag":993,"props":1379,"children":1380},{},[1381],{"type":997,"value":1382},"Proteins are involved in almost every process within living organisms, making them vital for life.",{"type":992,"tag":993,"props":1384,"children":1385},{},[1386,1388,1392],{"type":997,"value":1387},"One of the primary roles of proteins is to act as enzymes. ",{"type":992,"tag":1004,"props":1389,"children":1390},{},[1391],{"type":997,"value":327},{"type":997,"value":1393}," are proteins that speed up chemical reactions in the body, which is essential for metabolism. Without enzymes, reactions would occur too slowly to sustain life.",{"type":992,"tag":993,"props":1395,"children":1396},{},[1397],{"type":997,"value":1398},"For example, digestive enzymes help break down food into nutrients that the body can use for energy, growth, and repair.",{"title":986,"searchDepth":25,"depth":25,"links":1400},[],{"id":247,"data":248,"type":35,"maxContentLevel":19,"version":35,"reviews":251,"parsed":1402},{"data":1403,"body":1405,"toc":1467},{"title":986,"description":1404},"Proteins also provide structural support to cells and tissues. For instance, collagen is a protein that gives strength and structure to skin, bones, and connective tissues.",{"type":989,"children":1406},[1407,1419,1427,1436,1441,1450,1459],{"type":992,"tag":993,"props":1408,"children":1409},{},[1410,1412,1417],{"type":997,"value":1411},"Proteins also provide structural support to cells and tissues. For instance, ",{"type":992,"tag":1004,"props":1413,"children":1414},{},[1415],{"type":997,"value":1416},"collagen",{"type":997,"value":1418}," is a protein that gives strength and structure to skin, bones, and connective tissues.",{"type":992,"tag":993,"props":1420,"children":1421},{},[1422],{"type":992,"tag":1015,"props":1423,"children":1426},{"alt":1017,"src":1424,"title":1425},"image://2a25ce6e-062a-4ec9-b26c-ccd89726309f","Collagen. Image by Laboratoires Servier (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1428,"children":1429},{},[1430,1434],{"type":992,"tag":1004,"props":1431,"children":1432},{},[1433],{"type":997,"value":276},{"type":997,"value":1435},", another protein, is found in hair, nails, and the outer layer of skin, providing protection and durability.",{"type":992,"tag":993,"props":1437,"children":1438},{},[1439],{"type":997,"value":1440},"These structural proteins help maintain the shape and integrity of cells and tissues, which is crucial for the proper functioning of an organism.",{"type":992,"tag":993,"props":1442,"children":1443},{},[1444,1448],{"type":992,"tag":1004,"props":1445,"children":1446},{},[1447],{"type":997,"value":273},{"type":997,"value":1449}," are another important type of protein. They help move substances across cell membranes and throughout the body.",{"type":992,"tag":993,"props":1451,"children":1452},{},[1453,1457],{"type":992,"tag":1004,"props":1454,"children":1455},{},[1456],{"type":997,"value":334},{"type":997,"value":1458},", a transport protein in red blood cells, carries oxygen from the lungs to the rest of the body and brings carbon dioxide back to the lungs for exhalation. This transport of gases is vital for respiration and energy production in cells.",{"type":992,"tag":993,"props":1460,"children":1461},{},[1462],{"type":992,"tag":1015,"props":1463,"children":1466},{"alt":1017,"src":1464,"title":1465},"image://1ef4516d-d3be-4262-b9fe-cbca8532502b","Hemoglobin (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons",[],{"title":986,"searchDepth":25,"depth":25,"links":1468},[],{"id":294,"data":295,"type":35,"maxContentLevel":19,"version":35,"reviews":298,"parsed":1470},{"data":1471,"body":1473,"toc":1533},{"title":986,"description":1472},"Proteins also play a key role in cell signaling and communication.",{"type":989,"children":1474},[1475,1479,1495,1500,1519,1524],{"type":992,"tag":993,"props":1476,"children":1477},{},[1478],{"type":997,"value":1472},{"type":992,"tag":993,"props":1480,"children":1481},{},[1482,1486,1488,1493],{"type":992,"tag":1004,"props":1483,"children":1484},{},[1485],{"type":997,"value":309},{"type":997,"value":1487}," on the surface of cells bind to ",{"type":992,"tag":1004,"props":1489,"children":1490},{},[1491],{"type":997,"value":1492},"signaling molecules",{"type":997,"value":1494},", such as hormones, and transmit messages into the cell.",{"type":992,"tag":993,"props":1496,"children":1497},{},[1498],{"type":997,"value":1499},"This process helps cells respond to changes in their environment and coordinate activities within the organism.",{"type":992,"tag":993,"props":1501,"children":1502},{},[1503,1505,1510,1512,1517],{"type":997,"value":1504},"For example, insulin is a ",{"type":992,"tag":1004,"props":1506,"children":1507},{},[1508],{"type":997,"value":1509},"regulatory protein",{"type":997,"value":1511}," or ",{"type":992,"tag":1004,"props":1513,"children":1514},{},[1515],{"type":997,"value":1516},"hormone",{"type":997,"value":1518},", that controls blood sugar levels by signaling cells to take up glucose.",{"type":992,"tag":993,"props":1520,"children":1521},{},[1522],{"type":997,"value":1523},"In addition to these roles, proteins are involved in the immune response.",{"type":992,"tag":993,"props":1525,"children":1526},{},[1527,1531],{"type":992,"tag":1004,"props":1528,"children":1529},{},[1530],{"type":997,"value":306},{"type":997,"value":1532}," are proteins that recognize and neutralize foreign invaders, such as bacteria and viruses, protecting the body from infections. This defense mechanism is essential for maintaining health and preventing disease.",{"title":986,"searchDepth":25,"depth":25,"links":1534},[],{"id":315,"data":316,"type":35,"maxContentLevel":19,"version":35,"reviews":319,"parsed":1536},{"data":1537,"body":1539,"toc":1577},{"title":986,"description":1538},"Proteins are incredibly versatile because they can fold into a wide variety of shapes, allowing them to interact specifically with other molecules.",{"type":989,"children":1540},[1541,1545,1550,1562,1567,1572],{"type":992,"tag":993,"props":1542,"children":1543},{},[1544],{"type":997,"value":1538},{"type":992,"tag":993,"props":1546,"children":1547},{},[1548],{"type":997,"value":1549},"This specificity is crucial for the regulation of cellular processes.",{"type":992,"tag":993,"props":1551,"children":1552},{},[1553,1555,1560],{"type":997,"value":1554},"For example, ",{"type":992,"tag":1004,"props":1556,"children":1557},{},[1558],{"type":997,"value":1559},"enzymes",{"type":997,"value":1561}," have active sites that bind to specific substrates, ensuring that biochemical reactions occur with precision and efficiency.",{"type":992,"tag":993,"props":1563,"children":1564},{},[1565],{"type":997,"value":1566},"Moreover, proteins can change their shape in response to environmental conditions or interactions with other molecules.",{"type":992,"tag":993,"props":1568,"children":1569},{},[1570],{"type":997,"value":1571},"These changes can activate or deactivate the protein's function, providing a mechanism for regulating cellular activities.",{"type":992,"tag":993,"props":1573,"children":1574},{},[1575],{"type":997,"value":1576},"For instance, the binding of a hormone to its receptor can trigger a series of events inside the cell, leading to a specific response.",{"title":986,"searchDepth":25,"depth":25,"links":1578},[],{"id":347,"data":348,"type":25,"version":19,"maxContentLevel":19,"summaryPage":350,"introPage":358,"pages":1580},[1581,1676,1733,1769],{"id":366,"data":367,"type":35,"maxContentLevel":19,"version":35,"reviews":370,"parsed":1582},{"data":1583,"body":1585,"toc":1674},{"title":986,"description":1584},"We already touched upon carbohydrates in the orb focused on carbon. This section is going to go into a little more depth.\nCarbohydrates are essential molecules that play a crucial role in the characteristics of life, particularly in energy processing, growth and development, and response to stimuli.",{"type":989,"children":1586},[1587,1608,1629,1637,1642,1657,1669],{"type":992,"tag":993,"props":1588,"children":1589},{},[1590,1592,1597,1599,1603,1606],{"type":997,"value":1591},"We already touched upon carbohydrates in the orb focused on ",{"type":992,"tag":1004,"props":1593,"children":1594},{},[1595],{"type":997,"value":1596},"carbon.",{"type":997,"value":1598}," This section is going to go into a little more depth.",{"type":992,"tag":1600,"props":1601,"children":1602},"br",{},[],{"type":992,"tag":1600,"props":1604,"children":1605},{},[],{"type":997,"value":1607},"\nCarbohydrates are essential molecules that play a crucial role in the characteristics of life, particularly in energy processing, growth and development, and response to stimuli.",{"type":992,"tag":993,"props":1609,"children":1610},{},[1611,1613,1617,1618,1622,1623,1627],{"type":997,"value":1612},"They are composed of ",{"type":992,"tag":1004,"props":1614,"children":1615},{},[1616],{"type":997,"value":1008},{"type":997,"value":1087},{"type":992,"tag":1004,"props":1619,"children":1620},{},[1621],{"type":997,"value":1274},{"type":997,"value":1100},{"type":992,"tag":1004,"props":1624,"children":1625},{},[1626],{"type":997,"value":1165},{"type":997,"value":1628},", and are found in foods like fruits, vegetables, grains, and dairy products.",{"type":992,"tag":993,"props":1630,"children":1631},{},[1632],{"type":992,"tag":1015,"props":1633,"children":1636},{"alt":1017,"src":1634,"title":1635},"image://b52cfb6d-8ae1-4993-b5ce-e5488a484d5f","Assorted grains. Image by Fir0002 (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1638,"children":1639},{},[1640],{"type":997,"value":1641},"One of the primary roles of carbohydrates is to provide energy.",{"type":992,"tag":993,"props":1643,"children":1644},{},[1645,1649,1651,1655],{"type":992,"tag":1004,"props":1646,"children":1647},{},[1648],{"type":997,"value":1289},{"type":997,"value":1650},", such as glucose, are quickly absorbed by the body and used as a direct source of energy. ",{"type":992,"tag":1004,"props":1652,"children":1653},{},[1654],{"type":997,"value":157},{"type":997,"value":1656}," is especially important because it is the main fuel for our cells.",{"type":992,"tag":993,"props":1658,"children":1659},{},[1660,1662,1667],{"type":997,"value":1661},"During ",{"type":992,"tag":1004,"props":1663,"children":1664},{},[1665],{"type":997,"value":1666},"cellular respiration",{"type":997,"value":1668},", glucose is broken down to produce adenosine triphosphate (ATP), which cells use to power various activities, such as muscle contraction and nerve function.",{"type":992,"tag":993,"props":1670,"children":1671},{},[1672],{"type":997,"value":1673},"This immediate energy supply is vital for everyday activities and overall bodily functions.",{"title":986,"searchDepth":25,"depth":25,"links":1675},[],{"id":412,"data":413,"type":35,"maxContentLevel":19,"version":25,"reviews":416,"parsed":1677},{"data":1678,"body":1680,"toc":1731},{"title":986,"description":1679},"Carbohydrates also come in more complex forms, such as starches and glycogen, which serve as energy storage molecules.",{"type":989,"children":1681},[1682,1686,1696,1704,1709,1721,1726],{"type":992,"tag":993,"props":1683,"children":1684},{},[1685],{"type":997,"value":1679},{"type":992,"tag":993,"props":1687,"children":1688},{},[1689,1694],{"type":992,"tag":1004,"props":1690,"children":1691},{},[1692],{"type":997,"value":1693},"Plants store energy in the form of starch",{"type":997,"value":1695},", which is found in foods like potatoes, rice, and corn.",{"type":992,"tag":993,"props":1697,"children":1698},{},[1699],{"type":992,"tag":1015,"props":1700,"children":1703},{"alt":1017,"src":1701,"title":1702},"image://b990e2f8-0991-4147-94a2-a39d1dbe387d","Cornstarch mixed with water. Image by kalaya (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1705,"children":1706},{},[1707],{"type":997,"value":1708},"When we eat these foods, our bodies break down the starch into glucose, which can then be used for energy.",{"type":992,"tag":993,"props":1710,"children":1711},{},[1712,1714,1719],{"type":997,"value":1713},"Animals, including humans, ",{"type":992,"tag":1004,"props":1715,"children":1716},{},[1717],{"type":997,"value":1718},"store energy in the form of glycogen",{"type":997,"value":1720},", primarily in the liver and muscles.",{"type":992,"tag":993,"props":1722,"children":1723},{},[1724],{"type":997,"value":1725},"When the body needs energy, glycogen is broken down into glucose to maintain blood sugar levels and provide fuel for cells.",{"type":992,"tag":993,"props":1727,"children":1728},{},[1729],{"type":997,"value":1730},"This stored energy is crucial for sustaining bodily functions during periods when food intake is low.",{"title":986,"searchDepth":25,"depth":25,"links":1732},[],{"id":442,"data":443,"type":35,"maxContentLevel":19,"version":35,"reviews":446,"parsed":1734},{"data":1735,"body":1737,"toc":1767},{"title":986,"description":1736},"In addition to energy storage, carbohydrates provide structural support, which is closely related to the growth and development of living organisms.",{"type":989,"children":1738},[1739,1743,1754,1759],{"type":992,"tag":993,"props":1740,"children":1741},{},[1742],{"type":997,"value":1736},{"type":992,"tag":993,"props":1744,"children":1745},{},[1746,1748,1752],{"type":997,"value":1747},"For example, as we saw in the previous orb on carbon, ",{"type":992,"tag":1004,"props":1749,"children":1750},{},[1751],{"type":997,"value":1315},{"type":997,"value":1753}," is a carbohydrate that makes up the cell walls of plants. It gives plants their rigidity and strength, allowing them to stand upright and grow.",{"type":992,"tag":993,"props":1755,"children":1756},{},[1757],{"type":997,"value":1758},"Although humans cannot digest cellulose, it is an important part of our diet as dietary fiber, which helps maintain a healthy digestive system by promoting regular bowel movements and preventing constipation.",{"type":992,"tag":993,"props":1760,"children":1761},{},[1762],{"type":992,"tag":1015,"props":1763,"children":1766},{"alt":1017,"src":1764,"title":1765},"image://6813c562-6301-4230-b328-cc0e3399dade","The outer husks of corn, primarily made from cellulose, cannot be digested by humans. Starr-160707-0054-Zea mays-Hawaiian Supersweet hybrid ears harvested-Hawea Pl Olinda-Maui (29632280186) by Forest and Kim Starr (CC BY 3.0 us) \u003Chttps://creativecommons.org/licenses/by/3.0/us/deed.en>, via Wikimedia Commons",[],{"title":986,"searchDepth":25,"depth":25,"links":1768},[],{"id":463,"data":464,"type":35,"maxContentLevel":19,"version":19,"reviews":467,"parsed":1770},{"data":1771,"body":1773,"toc":1821},{"title":986,"description":1772},"Carbohydrates also play a role in cell recognition and communication.",{"type":989,"children":1774},[1775,1786,1803,1811,1816],{"type":992,"tag":993,"props":1776,"children":1777},{},[1778,1780,1785],{"type":997,"value":1779},"Carbohydrates also play a role in ",{"type":992,"tag":1004,"props":1781,"children":1782},{},[1783],{"type":997,"value":1784},"cell recognition and communication",{"type":997,"value":1010},{"type":992,"tag":993,"props":1787,"children":1788},{},[1789,1791,1796,1797,1802],{"type":997,"value":1790},"On the surface of cells, carbohydrates are often attached to proteins and lipids, forming structures known as ",{"type":992,"tag":1004,"props":1792,"children":1793},{},[1794],{"type":997,"value":1795},"glycoproteins",{"type":997,"value":1310},{"type":992,"tag":1004,"props":1798,"children":1799},{},[1800],{"type":997,"value":1801},"glycolipids",{"type":997,"value":1010},{"type":992,"tag":993,"props":1804,"children":1805},{},[1806],{"type":992,"tag":1015,"props":1807,"children":1810},{"alt":1017,"src":1808,"title":1809},"image://c5c55821-1ad8-4459-a0da-3731b4fcf04c","A cell membrane with glycoproteins and glycolipids attatched. Image: OpenStax, CC BY 4.0 \u003Chttps://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1812,"children":1813},{},[1814],{"type":997,"value":1815},"These structures help cells recognize and interact with each other, which is important for the immune system and other cellular processes.",{"type":992,"tag":993,"props":1817,"children":1818},{},[1819],{"type":997,"value":1820},"For instance, they help the immune system distinguish between the body's own cells and foreign invaders, such as bacteria and viruses.",{"title":986,"searchDepth":25,"depth":25,"links":1822},[],{"id":494,"data":495,"type":25,"version":35,"maxContentLevel":19,"summaryPage":497,"introPage":505,"pages":1824},[1825,1890,1935,1991],{"id":513,"data":514,"type":35,"maxContentLevel":19,"version":35,"reviews":517,"parsed":1826},{"data":1827,"body":1829,"toc":1888},{"title":986,"description":1828},"Nucleic acids are essential molecules in all living things because they store and pass on genetic information, guiding how cells function and reproduce.",{"type":989,"children":1830},[1831,1840,1859,1878,1883],{"type":992,"tag":993,"props":1832,"children":1833},{},[1834,1838],{"type":992,"tag":1004,"props":1835,"children":1836},{},[1837],{"type":997,"value":857},{"type":997,"value":1839}," are essential molecules in all living things because they store and pass on genetic information, guiding how cells function and reproduce.",{"type":992,"tag":993,"props":1841,"children":1842},{},[1843,1845,1850,1852,1857],{"type":997,"value":1844},"The two main types of nucleic acids are ",{"type":992,"tag":1004,"props":1846,"children":1847},{},[1848],{"type":997,"value":1849},"DNA",{"type":997,"value":1851}," (deoxyribonucleic acid) and ",{"type":992,"tag":1004,"props":1853,"children":1854},{},[1855],{"type":997,"value":1856},"RNA",{"type":997,"value":1858}," (ribonucleic acid).",{"type":992,"tag":993,"props":1860,"children":1861},{},[1862,1864,1869,1871,1876],{"type":997,"value":1863},"The \"",{"type":992,"tag":1004,"props":1865,"children":1866},{},[1867],{"type":997,"value":1868},"acid",{"type":997,"value":1870},"\" in nucleic acids comes from the phosphate group, which can ",{"type":992,"tag":1004,"props":1872,"children":1873},{},[1874],{"type":997,"value":1875},"lose a hydrogen ion",{"type":997,"value":1877},", leaving it with a negative charge.",{"type":992,"tag":993,"props":1879,"children":1880},{},[1881],{"type":997,"value":1882},"This negative charge gives the molecule its acidic properties and allows it to interact with water and other charged molecules in the cell.",{"type":992,"tag":993,"props":1884,"children":1885},{},[1886],{"type":997,"value":1887},"This interaction is important for the nucleic acid's ability to dissolve in water and function properly in the cell.",{"title":986,"searchDepth":25,"depth":25,"links":1889},[],{"id":552,"data":553,"type":35,"maxContentLevel":19,"version":35,"reviews":556,"parsed":1891},{"data":1892,"body":1894,"toc":1933},{"title":986,"description":1893},"Nucleic acids are made up of smaller units called nucleotides. Each nucleotide has three parts: a sugar, a phosphate group, and a nitrogenous base.",{"type":989,"children":1895},[1896,1908,1916,1928],{"type":992,"tag":993,"props":1897,"children":1898},{},[1899,1901,1906],{"type":997,"value":1900},"Nucleic acids are made up of smaller units called ",{"type":992,"tag":1004,"props":1902,"children":1903},{},[1904],{"type":997,"value":1905},"nucleotides",{"type":997,"value":1907},". Each nucleotide has three parts: a sugar, a phosphate group, and a nitrogenous base.",{"type":992,"tag":993,"props":1909,"children":1910},{},[1911],{"type":992,"tag":1015,"props":1912,"children":1915},{"alt":1017,"src":1913,"title":1914},"image://9a072f60-44be-475e-aeb5-77e9856af9d6","The structure of nucleotides. Image: OpenStax College, CC BY 3.0 \u003Chttps://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1917,"children":1918},{},[1919,1921,1926],{"type":997,"value":1920},"DNA is structured like a twisted ladder, known as a ",{"type":992,"tag":1004,"props":1922,"children":1923},{},[1924],{"type":997,"value":1925},"double helix",{"type":997,"value":1927},". The sugar and phosphate groups form the sides of the ladder, creating a long chain, while the nitrogenous bases form the rungs.",{"type":992,"tag":993,"props":1929,"children":1930},{},[1931],{"type":997,"value":1932},"The term \"nitrogenous\" refers to the fact that these bases (the rungs on the ladder) contain nitrogen atoms.",{"title":986,"searchDepth":25,"depth":25,"links":1934},[],{"id":569,"data":570,"type":35,"maxContentLevel":19,"version":35,"reviews":573,"parsed":1936},{"data":1937,"body":1939,"toc":1989},{"title":986,"description":1938},"The nitrogenous bases are the key to the genetic code because they pair up in specific ways to store information. In DNA, the bases are adenine (A), thymine (T), cytosine (C), and guanine (G).",{"type":989,"children":1940},[1941,1952,1963,1971,1976,1981],{"type":992,"tag":993,"props":1942,"children":1943},{},[1944,1946,1950],{"type":997,"value":1945},"The nitrogenous bases are the key to the genetic code because they pair up in specific ways to store information. In ",{"type":992,"tag":1004,"props":1947,"children":1948},{},[1949],{"type":997,"value":1849},{"type":997,"value":1951},", the bases are adenine (A), thymine (T), cytosine (C), and guanine (G).",{"type":992,"tag":993,"props":1953,"children":1954},{},[1955,1957,1961],{"type":997,"value":1956},"In ",{"type":992,"tag":1004,"props":1958,"children":1959},{},[1960],{"type":997,"value":1856},{"type":997,"value":1962},", thymine is replaced by uracil (U).",{"type":992,"tag":993,"props":1964,"children":1965},{},[1966],{"type":992,"tag":1015,"props":1967,"children":1970},{"alt":1017,"src":1968,"title":1969},"image://af888ad4-ae4a-4b1b-8695-4d8b9bd5bbc5","The nitrogenous base pairings. Image: Sponk, CC BY-SA 3.0 \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":1972,"children":1973},{},[1974],{"type":997,"value":1975},"In the ladder structure of DNA, adenine pairs with thymine, and cytosine pairs with guanine.",{"type":992,"tag":993,"props":1977,"children":1978},{},[1979],{"type":997,"value":1980},"This stable structure allows DNA to securely store genetic information. When needed, the two strands of the DNA can separate to allow the information to be copied or used to make proteins.",{"type":992,"tag":993,"props":1982,"children":1983},{},[1984],{"type":992,"tag":1015,"props":1985,"children":1988},{"alt":1017,"src":1986,"title":1987},"image://34c2582c-7f75-4296-883a-110341ab3d2b","Nucleic acids - Transcription by Laboratoires Servier (CC BY-SA 3.0) \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"title":986,"searchDepth":25,"depth":25,"links":1990},[],{"id":588,"data":589,"type":35,"maxContentLevel":19,"version":35,"reviews":592,"parsed":1992},{"data":1993,"body":1995,"toc":2041},{"title":986,"description":1994},"RNA, on the other hand, is usually single-stranded and more flexible. Because of this flexibility, RNA can fold into various shapes, enabling it to perform different functions within the cell.",{"type":989,"children":1996},[1997,2006,2011,2021,2031],{"type":992,"tag":993,"props":1998,"children":1999},{},[2000,2004],{"type":992,"tag":1004,"props":2001,"children":2002},{},[2003],{"type":997,"value":1856},{"type":997,"value":2005},", on the other hand, is usually single-stranded and more flexible. Because of this flexibility, RNA can fold into various shapes, enabling it to perform different functions within the cell.",{"type":992,"tag":993,"props":2007,"children":2008},{},[2009],{"type":997,"value":2010},"There are three main types of RNA, each with a specific role:",{"type":992,"tag":993,"props":2012,"children":2013},{},[2014,2019],{"type":992,"tag":1004,"props":2015,"children":2016},{},[2017],{"type":997,"value":2018},"Messenger RNA",{"type":997,"value":2020}," (mRNA): mRNA carries genetic instructions from DNA to the ribosomes, where proteins are synthesized. It acts as a template for assembling amino acids in the correct order to produce a specific protein.",{"type":992,"tag":993,"props":2022,"children":2023},{},[2024,2029],{"type":992,"tag":1004,"props":2025,"children":2026},{},[2027],{"type":997,"value":2028},"Ribosomal RNA",{"type":997,"value":2030}," (rRNA): rRNA is a key component of ribosomes, the cellular structures where proteins are made. rRNA helps to align the mRNA and the ribosomes and catalyzes the formation of the bonds between amino acids.",{"type":992,"tag":993,"props":2032,"children":2033},{},[2034,2039],{"type":992,"tag":1004,"props":2035,"children":2036},{},[2037],{"type":997,"value":2038},"Transfer RNA",{"type":997,"value":2040}," (tRNA): tRNA transports amino acids to the ribosome during protein synthesis. Each tRNA molecule recognizes specific sequences of mRNA and ensures that the correct amino acid is added to the growing protein chain.",{"title":986,"searchDepth":25,"depth":25,"links":2042},[],{"id":635,"data":636,"type":25,"version":25,"maxContentLevel":19,"summaryPage":638,"introPage":646,"pages":2044},[2045,2116,2225],{"id":654,"data":655,"type":35,"maxContentLevel":19,"version":35,"reviews":658,"parsed":2046},{"data":2047,"body":2049,"toc":2114},{"title":986,"description":2048},"We’re going to briefly move away from the organic molecules crucial to life to examine a fundamental molecule that will enhance your understanding of later sections, such as lipids. This molecule is water.",{"type":989,"children":2050},[2051,2062,2067,2079,2087,2099,2104,2109],{"type":992,"tag":993,"props":2052,"children":2053},{},[2054,2056,2061],{"type":997,"value":2055},"We’re going to briefly move away from the organic molecules crucial to life to examine a fundamental molecule that will enhance your understanding of later sections, such as lipids. This molecule is ",{"type":992,"tag":1004,"props":2057,"children":2058},{},[2059],{"type":997,"value":2060},"water",{"type":997,"value":1010},{"type":992,"tag":993,"props":2063,"children":2064},{},[2065],{"type":997,"value":2066},"Water is essential for life due to its unique properties that directly support living organisms.",{"type":992,"tag":993,"props":2068,"children":2069},{},[2070,2072,2077],{"type":997,"value":2071},"One of the key characteristics of water is its ",{"type":992,"tag":1004,"props":2073,"children":2074},{},[2075],{"type":997,"value":2076},"polarity",{"type":997,"value":2078},". A water molecule is made up of one oxygen atom and two hydrogen atoms. These atoms share electrons, but not equally, which gives the oxygen side of the molecule a slight negative charge and the hydrogen side a slight positive charge.",{"type":992,"tag":993,"props":2080,"children":2081},{},[2082],{"type":992,"tag":1015,"props":2083,"children":2086},{"alt":1017,"src":2084,"title":2085},"image://befaa48c-afa2-4395-8210-44bd7f4356a7","Water molecule. The oxygen side of the molecule a slight negative charge and the hydrogen side a slight positive charge. Image: Riccardo Rovinetti, CC BY-SA 3.0 \u003Chttps://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":2088,"children":2089},{},[2090,2092,2097],{"type":997,"value":2091},"This makes water a ",{"type":992,"tag":1004,"props":2093,"children":2094},{},[2095],{"type":997,"value":2096},"polar molecule",{"type":997,"value":2098},", meaning it has a positive and a negative side, similar to a magnet.",{"type":992,"tag":993,"props":2100,"children":2101},{},[2102],{"type":997,"value":2103},"Because of its polarity, water can form hydrogen bonds with other water molecules and with other polar substances. These bonds are weak attractions that allow water to dissolve many substances, making it an excellent solvent.",{"type":992,"tag":993,"props":2105,"children":2106},{},[2107],{"type":997,"value":2108},"For example, when salt is added to water, the water molecules surround and separate the salt's ions, causing the salt to dissolve.",{"type":992,"tag":993,"props":2110,"children":2111},{},[2112],{"type":997,"value":2113},"This ability to dissolve substances is crucial for transporting nutrients and removing waste in living organisms, ensuring that cells get the materials they need to function and stay healthy.",{"title":986,"searchDepth":25,"depth":25,"links":2115},[],{"id":693,"data":694,"type":35,"maxContentLevel":19,"version":25,"reviews":697,"parsed":2117},{"data":2118,"body":2120,"toc":2223},{"title":986,"description":2119},"Water also has a high specific heat capacity, meaning it can absorb a lot of heat before its temperature increases. This property helps stabilize temperatures in organisms and their environments.",{"type":989,"children":2121},[2122,2134,2146,2163,2186,2191,2199,2215],{"type":992,"tag":993,"props":2123,"children":2124},{},[2125,2127,2132],{"type":997,"value":2126},"Water also has a ",{"type":992,"tag":1004,"props":2128,"children":2129},{},[2130],{"type":997,"value":2131},"high specific heat capacity",{"type":997,"value":2133},", meaning it can absorb a lot of heat before its temperature increases. This property helps stabilize temperatures in organisms and their environments.",{"type":992,"tag":993,"props":2135,"children":2136},{},[2137,2139,2144],{"type":997,"value":2138},"For instance, the large amounts of water in the human body ",{"type":992,"tag":1004,"props":2140,"children":2141},{},[2142],{"type":997,"value":2143},"help maintain a stable internal temperature",{"type":997,"value":2145},", which is vital for enzymes and metabolic processes to function properly.",{"type":992,"tag":993,"props":2147,"children":2148},{},[2149,2151,2156,2157,2162],{"type":997,"value":2150},"Another important feature of water is its ",{"type":992,"tag":1004,"props":2152,"children":2153},{},[2154],{"type":997,"value":2155},"cohesion",{"type":997,"value":1310},{"type":992,"tag":1004,"props":2158,"children":2159},{},[2160],{"type":997,"value":2161},"adhesion",{"type":997,"value":1010},{"type":992,"tag":993,"props":2164,"children":2165},{},[2166,2170,2172,2178,2180,2185],{"type":992,"tag":1004,"props":2167,"children":2168},{},[2169],{"type":997,"value":671},{"type":997,"value":2171}," is the ability of water molecules to stick to ",{"type":992,"tag":2173,"props":2174,"children":2175},"em",{},[2176],{"type":997,"value":2177},"other water molecules",{"type":997,"value":2179},", which creates ",{"type":992,"tag":1004,"props":2181,"children":2182},{},[2183],{"type":997,"value":2184},"surface tension",{"type":997,"value":1010},{"type":992,"tag":993,"props":2187,"children":2188},{},[2189],{"type":997,"value":2190},"This property is illustrated by the way small insects, like water striders, can walk on water without sinking. In living organisms, this surface tension is important for processes like the movement of water in plants.",{"type":992,"tag":993,"props":2192,"children":2193},{},[2194],{"type":992,"tag":1015,"props":2195,"children":2198},{"alt":1017,"src":2196,"title":2197},"image://2380ba8e-060d-4eae-b839-83d154344d85","Gerridae on a lake. Image by Olexandr Ostrovyi (CC BY 4.0) \u003Chttps://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":2200,"children":2201},{},[2202,2206,2208,2213],{"type":992,"tag":1004,"props":2203,"children":2204},{},[2205],{"type":997,"value":672},{"type":997,"value":2207},", on the other hand, is water's ability to stick to ",{"type":992,"tag":2173,"props":2209,"children":2210},{},[2211],{"type":997,"value":2212},"different",{"type":997,"value":2214}," substances, which, along with cohesion, enables capillary action. In plants, capillary action helps water travel from the roots to the leaves, which is essential for transporting nutrients and maintaining plant health.",{"type":992,"tag":993,"props":2216,"children":2217},{},[2218],{"type":992,"tag":1015,"props":2219,"children":2222},{"alt":1017,"src":2220,"title":2221},"image://cd79fda1-0cfd-4c13-ac9e-5be40ff79298","Mangrove plant roots provides an island in the water (Public domain), via Wikimedia Commons",[],{"title":986,"searchDepth":25,"depth":25,"links":2224},[],{"id":737,"data":738,"type":35,"maxContentLevel":19,"version":35,"reviews":741,"parsed":2226},{"data":2227,"body":2229,"toc":2268},{"title":986,"description":2228},"Finally, water helps maintain pH balance in living organisms. pH measures how acidic or basic a solution is, and maintaining a stable pH is crucial for life.",{"type":989,"children":2230},[2231,2243,2251,2263],{"type":992,"tag":993,"props":2232,"children":2233},{},[2234,2236,2241],{"type":997,"value":2235},"Finally, water helps ",{"type":992,"tag":1004,"props":2237,"children":2238},{},[2239],{"type":997,"value":2240},"maintain pH balance",{"type":997,"value":2242}," in living organisms. pH measures how acidic or basic a solution is, and maintaining a stable pH is crucial for life.",{"type":992,"tag":993,"props":2244,"children":2245},{},[2246],{"type":992,"tag":1015,"props":2247,"children":2250},{"alt":1017,"src":2248,"title":2249},"image://bfddb423-7b46-47f6-b6bb-a7dd047d8370","216 pH Scale-01 by OpenStax College (CC BY 3.0) \u003Chttps://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":2252,"children":2253},{},[2254,2256,2261],{"type":997,"value":2255},"Water acts as a ",{"type":992,"tag":1004,"props":2257,"children":2258},{},[2259],{"type":997,"value":2260},"buffer",{"type":997,"value":2262},", absorbing excess hydrogen or hydroxide ions by surrounding them with water molecules, which helps to keep pH levels stable.",{"type":992,"tag":993,"props":2264,"children":2265},{},[2266],{"type":997,"value":2267},"This is important for maintaining the proper conditions for enzymes and other proteins to function, such as in human blood, where a stable pH of around 7.4 is necessary for the body to function effectively.",{"title":986,"searchDepth":25,"depth":25,"links":2269},[],{"id":774,"data":775,"type":25,"version":19,"maxContentLevel":19,"summaryPage":777,"introPage":785,"pages":2271},[2272,2359,2473,2540],{"id":793,"data":794,"type":35,"maxContentLevel":19,"version":35,"reviews":797,"parsed":2273},{"data":2274,"body":2276,"toc":2357},{"title":986,"description":2275},"Lipids are a group of molecules that don't mix well with water, making them essential for many biological functions.",{"type":989,"children":2277},[2278,2287,2292,2304,2309,2314,2322,2340,2352],{"type":992,"tag":993,"props":2279,"children":2280},{},[2281,2285],{"type":992,"tag":1004,"props":2282,"children":2283},{},[2284],{"type":997,"value":776},{"type":997,"value":2286}," are a group of molecules that don't mix well with water, making them essential for many biological functions.",{"type":992,"tag":993,"props":2288,"children":2289},{},[2290],{"type":997,"value":2291},"These molecules are mainly made up of hydrogen and carbon atoms.",{"type":992,"tag":993,"props":2293,"children":2294},{},[2295,2297,2302],{"type":997,"value":2296},"Because of this composition, lipids are ",{"type":992,"tag":1004,"props":2298,"children":2299},{},[2300],{"type":997,"value":2301},"nonpolar",{"type":997,"value":2303},", meaning they don't have a positive or negative charge that would allow them to interact with water molecules.",{"type":992,"tag":993,"props":2305,"children":2306},{},[2307],{"type":997,"value":2308},"Water is polar, which means it has regions of slight positive and negative charge, allowing water molecules to stick together.",{"type":992,"tag":993,"props":2310,"children":2311},{},[2312],{"type":997,"value":2313},"Since lipids are nonpolar, they don't interact well with water and, therefore, do not dissolve in it. Instead, they separate from water, similar to how oil separates from water in a mixture.",{"type":992,"tag":993,"props":2315,"children":2316},{},[2317],{"type":992,"tag":1015,"props":2318,"children":2321},{"alt":1017,"src":2319,"title":2320},"image://c43a6f4d-57b1-4fff-9d2d-477fdf7624c0","Oil separating from water. Image by Roger McLassus 1951 (CC BY-SA 3.0) \u003Chttp://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons",[],{"type":992,"tag":993,"props":2323,"children":2324},{},[2325,2327,2332,2333,2338],{"type":997,"value":2326},"This property is what makes lipids useful for ",{"type":992,"tag":1004,"props":2328,"children":2329},{},[2330],{"type":997,"value":2331},"forming barriers",{"type":997,"value":1303},{"type":992,"tag":1004,"props":2334,"children":2335},{},[2336],{"type":997,"value":2337},"cell membranes",{"type":997,"value":2339},", and storing energy in the body.",{"type":992,"tag":993,"props":2341,"children":2342},{},[2343,2345,2350],{"type":997,"value":2344},"Besides storing energy and forming membranes, lipids also ",{"type":992,"tag":1004,"props":2346,"children":2347},{},[2348],{"type":997,"value":2349},"insulate and protect",{"type":997,"value":2351},". For example, a layer of fat beneath the skin helps animals maintain their body temperature by reducing heat loss.",{"type":992,"tag":993,"props":2353,"children":2354},{},[2355],{"type":997,"value":2356},"Additionally, lipids cushion organs, providing a protective layer that absorbs shock.",{"title":986,"searchDepth":25,"depth":25,"links":2358},[],{"id":840,"data":841,"type":35,"maxContentLevel":19,"version":35,"reviews":844,"parsed":2360},{"data":2361,"body":2363,"toc":2471},{"title":986,"description":2362},"The main types of lipids include: fats, oils, waxes, phospholipids, and steroids, each with its own important role in living organisms.",{"type":989,"children":2364},[2365,2401,2412,2424,2443,2451,2461],{"type":992,"tag":993,"props":2366,"children":2367},{},[2368,2370,2375,2376,2381,2382,2387,2388,2393,2394,2399],{"type":997,"value":2369},"The main types of lipids include: ",{"type":992,"tag":1004,"props":2371,"children":2372},{},[2373],{"type":997,"value":2374},"fats",{"type":997,"value":1087},{"type":992,"tag":1004,"props":2377,"children":2378},{},[2379],{"type":997,"value":2380},"oils",{"type":997,"value":1087},{"type":992,"tag":1004,"props":2383,"children":2384},{},[2385],{"type":997,"value":2386},"waxes",{"type":997,"value":1087},{"type":992,"tag":1004,"props":2389,"children":2390},{},[2391],{"type":997,"value":2392},"phospholipids",{"type":997,"value":1100},{"type":992,"tag":1004,"props":2395,"children":2396},{},[2397],{"type":997,"value":2398},"steroids",{"type":997,"value":2400},", each with its own important role in living organisms.",{"type":992,"tag":993,"props":2402,"children":2403},{},[2404,2406,2411],{"type":997,"value":2405},"One key function of lipids is ",{"type":992,"tag":1004,"props":2407,"children":2408},{},[2409],{"type":997,"value":2410},"storing energy",{"type":997,"value":1010},{"type":992,"tag":993,"props":2413,"children":2414},{},[2415,2417,2422],{"type":997,"value":2416},"Fats, also called ",{"type":992,"tag":1004,"props":2418,"children":2419},{},[2420],{"type":997,"value":2421},"triglycerides",{"type":997,"value":2423},", are the primary way animals store energy.",{"type":992,"tag":993,"props":2425,"children":2426},{},[2427,2429,2434,2436,2441],{"type":997,"value":2428},"A fat molecule consists of a glycerol backbone connected to ",{"type":992,"tag":1004,"props":2430,"children":2431},{},[2432],{"type":997,"value":2433},"three fatty acid chains",{"type":997,"value":2435},". These ",{"type":992,"tag":1004,"props":2437,"children":2438},{},[2439],{"type":997,"value":2440},"fatty acids",{"type":997,"value":2442}," can be either saturated or unsaturated.",{"type":992,"tag":993,"props":2444,"children":2445},{},[2446],{"type":992,"tag":1015,"props":2447,"children":2450},{"alt":1017,"src":2448,"title":2449},"image://24c88545-a002-4e00-8516-248106858c5a","Butter and Oil - NCI Visuals Online (Public domain), via Wikimedia Commons",[],{"type":992,"tag":993,"props":2452,"children":2453},{},[2454,2459],{"type":992,"tag":1004,"props":2455,"children":2456},{},[2457],{"type":997,"value":2458},"Saturated fatty acids",{"type":997,"value":2460}," have no double bonds between the carbon atoms, so they are fully saturated with hydrogen atoms. This makes them straight, allowing them to pack tightly together, which is why saturated fats are usually solid at room temperature, like butter.",{"type":992,"tag":993,"props":2462,"children":2463},{},[2464,2469],{"type":992,"tag":1004,"props":2465,"children":2466},{},[2467],{"type":997,"value":2468},"Unsaturated fatty acids",{"type":997,"value":2470},", on the other hand, have one or more double bonds, creating bends in the chain that prevent tight packing, making them liquid at room temperature, like olive oil.",{"title":986,"searchDepth":25,"depth":25,"links":2472},[],{"id":894,"data":895,"type":35,"maxContentLevel":19,"version":19,"reviews":898,"parsed":2474},{"data":2475,"body":2477,"toc":2538},{"title":986,"description":2476},"Phospholipids are another important type of lipid, especially for forming cell membranes.",{"type":989,"children":2478},[2479,2489,2494,2513,2518,2526],{"type":992,"tag":993,"props":2480,"children":2481},{},[2482,2484],{"type":997,"value":2483},"Phospholipids are another important type of lipid, especially for ",{"type":992,"tag":1004,"props":2485,"children":2486},{},[2487],{"type":997,"value":2488},"forming cell membranes.",{"type":992,"tag":993,"props":2490,"children":2491},{},[2492],{"type":997,"value":2493},"A phospholipid molecule has a glycerol backbone, two fatty acid tails, and a phosphate group.",{"type":992,"tag":993,"props":2495,"children":2496},{},[2497,2499,2504,2506,2511],{"type":997,"value":2498},"The phosphate group is ",{"type":992,"tag":1004,"props":2500,"children":2501},{},[2502],{"type":997,"value":2503},"hydrophilic",{"type":997,"value":2505},", meaning it attracts water, while the fatty acid tails are ",{"type":992,"tag":1004,"props":2507,"children":2508},{},[2509],{"type":997,"value":2510},"hydrophobic",{"type":997,"value":2512},", meaning they repel water.",{"type":992,"tag":993,"props":2514,"children":2515},{},[2516],{"type":997,"value":2517},"This unique structure allows phospholipids to form double layers in water, with the fatty acid tails facing inward and the heads facing outward.",{"type":992,"tag":993,"props":2519,"children":2520},{},[2521],{"type":992,"tag":1015,"props":2522,"children":2525},{"alt":1017,"src":2523,"title":2524},"image://d96b1f4c-9f72-4c03-abcd-677ebc6d3bf0","Phospholipid structure of a cell membrane. Image: TvanBrussel (Copyrighted free use), via Wikimedia Commons",[],{"type":992,"tag":993,"props":2527,"children":2528},{},[2529,2531,2536],{"type":997,"value":2530},"This arrangement ",{"type":992,"tag":1004,"props":2532,"children":2533},{},[2534],{"type":997,"value":2535},"creates the cell membrane",{"type":997,"value":2537},", a barrier that controls what enters and leaves the cell.",{"title":986,"searchDepth":25,"depth":25,"links":2539},[],{"id":922,"data":923,"type":35,"maxContentLevel":19,"version":35,"reviews":926,"parsed":2541},{"data":2542,"body":2544,"toc":2619},{"title":986,"description":2543},"Steroids are a different kind of lipid with a structure made up of four connected carbon rings.",{"type":989,"children":2545},[2546,2555,2560,2585,2597,2609,2614],{"type":992,"tag":993,"props":2547,"children":2548},{},[2549,2553],{"type":992,"tag":1004,"props":2550,"children":2551},{},[2552],{"type":997,"value":854},{"type":997,"value":2554}," are a different kind of lipid with a structure made up of four connected carbon rings.",{"type":992,"tag":993,"props":2556,"children":2557},{},[2558],{"type":997,"value":2559},"Cholesterol is a well-known steroid that is crucial for cell membrane stability and fluidity.",{"type":992,"tag":993,"props":2561,"children":2562},{},[2563,2565,2570,2572,2577,2578,2583],{"type":997,"value":2564},"Cholesterol also serves as a building block for ",{"type":992,"tag":1004,"props":2566,"children":2567},{},[2568],{"type":997,"value":2569},"steroid hormones",{"type":997,"value":2571}," like ",{"type":992,"tag":1004,"props":2573,"children":2574},{},[2575],{"type":997,"value":2576},"testosterone",{"type":997,"value":1310},{"type":992,"tag":1004,"props":2579,"children":2580},{},[2581],{"type":997,"value":2582},"estrogen",{"type":997,"value":2584},", which regulate many body functions.",{"type":992,"tag":993,"props":2586,"children":2587},{},[2588,2590,2595],{"type":997,"value":2589},"Additionally, ",{"type":992,"tag":1004,"props":2591,"children":2592},{},[2593],{"type":997,"value":2594},"cholesterol",{"type":997,"value":2596}," is necessary for producing bile salts that help digest and absorb fats from food.",{"type":992,"tag":993,"props":2598,"children":2599},{},[2600,2602,2607],{"type":997,"value":2601},"Lipids such as steroids also play a role in ",{"type":992,"tag":1004,"props":2603,"children":2604},{},[2605],{"type":997,"value":2606},"communication between cells",{"type":997,"value":2608},". Some lipids act as signaling molecules, influencing how cells behave.",{"type":992,"tag":993,"props":2610,"children":2611},{},[2612],{"type":997,"value":2613},"For example, steroid hormones derived from cholesterol can enter cells and bind to receptors, causing changes in how genes are expressed and how the cell functions.",{"type":992,"tag":993,"props":2615,"children":2616},{},[2617],{"type":997,"value":2618},"This ability to signal is vital for maintaining balance in the body and coordinating complex biological responses.",{"title":986,"searchDepth":25,"depth":25,"links":2620},[],{"left":4,"top":4,"width":2622,"height":2622,"rotate":4,"vFlip":6,"hFlip":6,"body":2623},24,"\u003Cpath fill=\"none\" stroke=\"currentColor\" stroke-linecap=\"round\" stroke-linejoin=\"round\" stroke-width=\"2\" d=\"m9 18l6-6l-6-6\"/>",{"left":4,"top":4,"width":2622,"height":2622,"rotate":4,"vFlip":6,"hFlip":6,"body":2625},"\u003Cpath fill=\"none\" stroke=\"currentColor\" stroke-linecap=\"round\" stroke-linejoin=\"round\" stroke-width=\"2\" d=\"M4 5h16M4 12h16M4 19h16\"/>",1778228317403]