{"id":5012,"date":"2017-07-14T23:53:15","date_gmt":"2017-07-14T23:53:15","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/hccs-waymakerbiology1\/?post_type=chapter&#038;p=5012"},"modified":"2024-04-26T00:38:54","modified_gmt":"2024-04-26T00:38:54","slug":"the-calvin-cycle","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/chapter\/the-calvin-cycle\/","title":{"raw":"The Calvin Cycle","rendered":"The Calvin Cycle"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Describe the steps and processes in the Calvin Cycle<\/li>\r\n<\/ul>\r\n<\/div>\r\nAfter the energy from the sun is converted and packaged into ATP and NADPH, the cell has the fuel needed to build food in the form of carbohydrate molecules. The carbohydrate molecules made will have a backbone of carbon atoms. Where does the carbon come from? The carbon atoms used to build carbohydrate molecules comes from carbon dioxide, the gas that animals exhale with each breath. The Calvin cycle is the term used for the reactions of photosynthesis that use the energy stored by the light-dependent reactions to form glucose and other carbohydrate molecules. This process may also be called the light-independent reaction, as it does not directly require sunlight (but it does require the products produced from the light-dependent reactions).\r\n<h2>The Innerworkings of the Calvin Cycle<\/h2>\r\n[caption id=\"attachment_1183\" align=\"alignright\" width=\"450\"]<img class=\"wp-image-1183\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225212\/7-2-1.jpeg\" alt=\"This illustration shows that ATP and NADPH produced in the light reactions are used in the Calvin cycle to make sugar.\" width=\"450\" height=\"412\" \/> Figure 1. Light-dependent reactions harness energy from the sun to produce ATP and NADPH. These energy-carrying molecules travel into the stroma where the Calvin cycle reactions take place.[\/caption]\r\n\r\nIn plants, carbon dioxide (CO<sub>2<\/sub>) enters the chloroplast through the stomata and diffuses into the stroma of the chloroplast\u2014the site of the Calvin cycle reactions where sugar is synthesized. The reactions are named after the scientist who discovered them, and reference the fact that the reactions function as a cycle. Others call it the Calvin-Benson cycle to include the name of another scientist involved in its discovery (Figure 1).\r\n\r\nThe Calvin cycle reactions (Figure 2) can be organized into three basic stages: fixation, reduction, and regeneration. In the stroma, in addition to CO<sub>2<\/sub>, two other chemicals are present to initiate the Calvin cycle: an enzyme abbreviated RuBisCO, and the molecule ribulose bisphosphate (RuBP). RuBP has five atoms of carbon and a phosphate group on each end.\r\n\r\nRuBisCO catalyzes a reaction between CO<sub>2<\/sub> and RuBP, which forms a six-carbon compound that is immediately converted into two three-carbon compounds. This process is called carbon fixation, because CO<sub>2<\/sub> is \u201cfixed\u201d from its inorganic form into organic molecules.\r\n\r\nATP and NADPH use their stored energy to convert the three-carbon compound, 3-PGA, into another three-carbon compound called G3P. This type of reaction is called a reduction reaction, because it involves the gain of electrons. A reduction is the gain of an electron by an atom or molecule. The molecules of ADP and NAD<sup>+<\/sup>, resulting from the reduction reaction, return to the light-dependent reactions to be re-energized.\r\n\r\nOne of the G3P molecules leaves the Calvin cycle to contribute to the formation of the carbohydrate molecule, which is commonly glucose (C<sub>6<\/sub>H<sub>12<\/sub>O<sub>6<\/sub>). Because the carbohydrate molecule has six carbon atoms, it takes six turns of the Calvin cycle to make one carbohydrate molecule (one for each carbon dioxide molecule fixed). The remaining G3P molecules regenerate RuBP, which enables the system to prepare for the carbon-fixation step. ATP is also used in the regeneration of RuBP.\r\n\r\n[caption id=\"attachment_1185\" align=\"aligncenter\" width=\"800\"]<img class=\"wp-image-1185 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225302\/7-2-2.jpeg\" alt=\"This illustration shows a circular cycle with three stages. Three molecules of carbon dioxide enter the cycle. In the first stage, the enzyme RuBisCO incorporates the carbon dioxide into an organic molecule. Six ATP molecules are converted into six ADP molecules. In the second stage, the organic molecule is reduced. Six NADPH molecules are converted into six NADP+ ions and one hydrogen ion. Sugar is produced. In stage three, RuBP is regenerated, and three ATP molecules are converted into three ADP molecules. RuBP then starts the cycle again.\" width=\"800\" height=\"667\" \/> Figure 2. The Calvin cycle has three stages. In stage 1, the enzyme RuBisCO incorporates carbon dioxide into an organic molecule. In stage 2, the organic molecule is reduced. In stage 3, RuBP, the molecule that starts the cycle, is regenerated so that the cycle can continue.[\/caption]\r\n\r\nIn summary, it takes six turns of the Calvin cycle to fix six carbon atoms from CO<sub>2<\/sub>. These six turns require energy input from 12 ATP molecules and 12 NADPH molecules in the reduction step and 6 ATP molecules in the regeneration step.\r\n<div class=\"textbox shaded\">\r\n\r\nCheck out this\u00a0<a href=\"http:\/\/www.science.smith.edu\/departments\/Biology\/Bio231\/calvin.html\" target=\"_blank\" rel=\"noopener\">animation of the Calvin cycle<\/a>. Click Stage 1, Stage 2, and then Stage 3 to see G3P and ATP regenerate to form RuBP.\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Evolution in Action: Photosynthesis<\/h3>\r\n[caption id=\"attachment_1186\" align=\"alignright\" width=\"250\"]<img class=\"wp-image-1186\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225334\/7-2-3.jpeg\" alt=\"This photo shows a cactus.\" width=\"250\" height=\"328\" \/> Figure 3. Living in the harsh conditions of the desert has led plants like this cactus to evolve variations in reactions outside the Calvin cycle. These variations increase efficiency and help conserve water and energy. (credit: Piotr Wojtkowski)[\/caption]\r\n\r\nThe shared evolutionary history of all photosynthetic organisms is conspicuous, as the basic process has changed little over eras of time. Even between the giant tropical leaves in the rainforest and tiny cyanobacteria, the process and components of photosynthesis that use water as an electron donor remain largely the same. Photosystems function to absorb light and use electron transport chains to convert energy. The Calvin cycle reactions assemble carbohydrate molecules with this energy.\r\n\r\nHowever, as with all biochemical pathways, a variety of conditions leads to varied adaptations that affect the basic pattern. Photosynthesis in dry-climate plants (Figure 3) has evolved with adaptations that conserve water. In the harsh dry heat, every drop of water and precious energy must be used to survive. Two adaptations have evolved in such plants. In one form, a more efficient use of CO<sub>2<\/sub> allows plants to photosynthesize even when CO<sub>2<\/sub> is in short supply, as when the stomata are closed on hot days. The other adaptation performs preliminary reactions of the Calvin cycle at night, because opening the stomata at this time conserves water due to cooler temperatures. In addition, this adaptation has allowed plants to carry out low levels of photosynthesis without opening stomata at all, an extreme mechanism to face extremely dry periods.\r\n\r\n<\/div>\r\n<h2>Photosynthesis in Prokaryotes<\/h2>\r\nThe two parts of photosynthesis\u2014the light-dependent reactions and the Calvin cycle\u2014have been described, as they take place in chloroplasts. However, prokaryotes, such as cyanobacteria, lack membrane-bound organelles. Prokaryotic photosynthetic autotrophic organisms have infoldings of the plasma membrane for chlorophyll attachment and photosynthesis (Figure 4). It is here that organisms like cyanobacteria can carry out photosynthesis.\r\n\r\n[caption id=\"attachment_1187\" align=\"aligncenter\" width=\"500\"]<img class=\"wp-image-1187\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225424\/7-2-4.jpeg\" alt=\"This illustration shows a green ribbon, representing a folded membrane, with many folds stacked on top of another like a rope or hose. The photo shows an electron micrograph of a cleaved thylakoid membrane with similar folds from a unicellular organism\" width=\"500\" height=\"416\" \/> Figure 4. A photosynthetic prokaryote has infolded regions of the plasma membrane that function like thylakoids. Although these are not contained in an organelle, such as a chloroplast, all of the necessary components are present to carry out photosynthesis. (credit: scale-bar data from Matt Russell)[\/caption]\r\n\r\n&nbsp;\r\n<div class=\"textbox learning-objectives\">\r\n<h3>In Summary: The Calvin Cycle<\/h3>\r\nUsing the energy carriers formed in the first stage of photosynthesis, the Calvin cycle reactions fix CO<sub>2<\/sub> from the environment to build carbohydrate molecules. An enzyme, RuBisCO, catalyzes the fixation reaction, by combining CO<sub>2<\/sub> with RuBP. The resulting six-carbon compound is broken down into two three-carbon compounds, and the energy in ATP and NADPH is used to convert these molecules into G3P. One of the three-carbon molecules of G3P leaves the cycle to become a part of a carbohydrate molecule. The remaining G3P molecules stay in the cycle to be formed back into RuBP, which is ready to react with more CO<sub>2<\/sub>. Photosynthesis forms a balanced energy cycle with the process of cellular respiration. Plants are capable of both photosynthesis and cellular respiration, since they contain both chloroplasts and mitochondria.\r\n\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Question<\/h3>\r\nWhich part of the Calvin cycle would be affected if a cell could not produce the enzyme RuBisCO?\r\n\r\n[practice-area rows=\"4\"][\/practice-area]\r\n[reveal-answer q=\"968396\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"968396\"]None of the cycle could take place, because RuBisCO is essential in fixing carbon dioxide. Specifically, RuBisCO catalyzes the reaction between carbon dioxide and RuBP at the start of the cycle.\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/5d232a16-f62e-432e-b8a3-1020ad3de878\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Describe the steps and processes in the Calvin Cycle<\/li>\n<\/ul>\n<\/div>\n<p>After the energy from the sun is converted and packaged into ATP and NADPH, the cell has the fuel needed to build food in the form of carbohydrate molecules. The carbohydrate molecules made will have a backbone of carbon atoms. Where does the carbon come from? The carbon atoms used to build carbohydrate molecules comes from carbon dioxide, the gas that animals exhale with each breath. The Calvin cycle is the term used for the reactions of photosynthesis that use the energy stored by the light-dependent reactions to form glucose and other carbohydrate molecules. This process may also be called the light-independent reaction, as it does not directly require sunlight (but it does require the products produced from the light-dependent reactions).<\/p>\n<h2>The Innerworkings of the Calvin Cycle<\/h2>\n<div id=\"attachment_1183\" style=\"width: 460px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1183\" class=\"wp-image-1183\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225212\/7-2-1.jpeg\" alt=\"This illustration shows that ATP and NADPH produced in the light reactions are used in the Calvin cycle to make sugar.\" width=\"450\" height=\"412\" \/><\/p>\n<p id=\"caption-attachment-1183\" class=\"wp-caption-text\">Figure 1. Light-dependent reactions harness energy from the sun to produce ATP and NADPH. These energy-carrying molecules travel into the stroma where the Calvin cycle reactions take place.<\/p>\n<\/div>\n<p>In plants, carbon dioxide (CO<sub>2<\/sub>) enters the chloroplast through the stomata and diffuses into the stroma of the chloroplast\u2014the site of the Calvin cycle reactions where sugar is synthesized. The reactions are named after the scientist who discovered them, and reference the fact that the reactions function as a cycle. Others call it the Calvin-Benson cycle to include the name of another scientist involved in its discovery (Figure 1).<\/p>\n<p>The Calvin cycle reactions (Figure 2) can be organized into three basic stages: fixation, reduction, and regeneration. In the stroma, in addition to CO<sub>2<\/sub>, two other chemicals are present to initiate the Calvin cycle: an enzyme abbreviated RuBisCO, and the molecule ribulose bisphosphate (RuBP). RuBP has five atoms of carbon and a phosphate group on each end.<\/p>\n<p>RuBisCO catalyzes a reaction between CO<sub>2<\/sub> and RuBP, which forms a six-carbon compound that is immediately converted into two three-carbon compounds. This process is called carbon fixation, because CO<sub>2<\/sub> is \u201cfixed\u201d from its inorganic form into organic molecules.<\/p>\n<p>ATP and NADPH use their stored energy to convert the three-carbon compound, 3-PGA, into another three-carbon compound called G3P. This type of reaction is called a reduction reaction, because it involves the gain of electrons. A reduction is the gain of an electron by an atom or molecule. The molecules of ADP and NAD<sup>+<\/sup>, resulting from the reduction reaction, return to the light-dependent reactions to be re-energized.<\/p>\n<p>One of the G3P molecules leaves the Calvin cycle to contribute to the formation of the carbohydrate molecule, which is commonly glucose (C<sub>6<\/sub>H<sub>12<\/sub>O<sub>6<\/sub>). Because the carbohydrate molecule has six carbon atoms, it takes six turns of the Calvin cycle to make one carbohydrate molecule (one for each carbon dioxide molecule fixed). The remaining G3P molecules regenerate RuBP, which enables the system to prepare for the carbon-fixation step. ATP is also used in the regeneration of RuBP.<\/p>\n<div id=\"attachment_1185\" style=\"width: 810px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1185\" class=\"wp-image-1185 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225302\/7-2-2.jpeg\" alt=\"This illustration shows a circular cycle with three stages. Three molecules of carbon dioxide enter the cycle. In the first stage, the enzyme RuBisCO incorporates the carbon dioxide into an organic molecule. Six ATP molecules are converted into six ADP molecules. In the second stage, the organic molecule is reduced. Six NADPH molecules are converted into six NADP+ ions and one hydrogen ion. Sugar is produced. In stage three, RuBP is regenerated, and three ATP molecules are converted into three ADP molecules. RuBP then starts the cycle again.\" width=\"800\" height=\"667\" \/><\/p>\n<p id=\"caption-attachment-1185\" class=\"wp-caption-text\">Figure 2. The Calvin cycle has three stages. In stage 1, the enzyme RuBisCO incorporates carbon dioxide into an organic molecule. In stage 2, the organic molecule is reduced. In stage 3, RuBP, the molecule that starts the cycle, is regenerated so that the cycle can continue.<\/p>\n<\/div>\n<p>In summary, it takes six turns of the Calvin cycle to fix six carbon atoms from CO<sub>2<\/sub>. These six turns require energy input from 12 ATP molecules and 12 NADPH molecules in the reduction step and 6 ATP molecules in the regeneration step.<\/p>\n<div class=\"textbox shaded\">\n<p>Check out this\u00a0<a href=\"http:\/\/www.science.smith.edu\/departments\/Biology\/Bio231\/calvin.html\" target=\"_blank\" rel=\"noopener\">animation of the Calvin cycle<\/a>. Click Stage 1, Stage 2, and then Stage 3 to see G3P and ATP regenerate to form RuBP.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Evolution in Action: Photosynthesis<\/h3>\n<div id=\"attachment_1186\" style=\"width: 260px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1186\" class=\"wp-image-1186\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225334\/7-2-3.jpeg\" alt=\"This photo shows a cactus.\" width=\"250\" height=\"328\" \/><\/p>\n<p id=\"caption-attachment-1186\" class=\"wp-caption-text\">Figure 3. Living in the harsh conditions of the desert has led plants like this cactus to evolve variations in reactions outside the Calvin cycle. These variations increase efficiency and help conserve water and energy. (credit: Piotr Wojtkowski)<\/p>\n<\/div>\n<p>The shared evolutionary history of all photosynthetic organisms is conspicuous, as the basic process has changed little over eras of time. Even between the giant tropical leaves in the rainforest and tiny cyanobacteria, the process and components of photosynthesis that use water as an electron donor remain largely the same. Photosystems function to absorb light and use electron transport chains to convert energy. The Calvin cycle reactions assemble carbohydrate molecules with this energy.<\/p>\n<p>However, as with all biochemical pathways, a variety of conditions leads to varied adaptations that affect the basic pattern. Photosynthesis in dry-climate plants (Figure 3) has evolved with adaptations that conserve water. In the harsh dry heat, every drop of water and precious energy must be used to survive. Two adaptations have evolved in such plants. In one form, a more efficient use of CO<sub>2<\/sub> allows plants to photosynthesize even when CO<sub>2<\/sub> is in short supply, as when the stomata are closed on hot days. The other adaptation performs preliminary reactions of the Calvin cycle at night, because opening the stomata at this time conserves water due to cooler temperatures. In addition, this adaptation has allowed plants to carry out low levels of photosynthesis without opening stomata at all, an extreme mechanism to face extremely dry periods.<\/p>\n<\/div>\n<h2>Photosynthesis in Prokaryotes<\/h2>\n<p>The two parts of photosynthesis\u2014the light-dependent reactions and the Calvin cycle\u2014have been described, as they take place in chloroplasts. However, prokaryotes, such as cyanobacteria, lack membrane-bound organelles. Prokaryotic photosynthetic autotrophic organisms have infoldings of the plasma membrane for chlorophyll attachment and photosynthesis (Figure 4). It is here that organisms like cyanobacteria can carry out photosynthesis.<\/p>\n<div id=\"attachment_1187\" style=\"width: 510px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1187\" class=\"wp-image-1187\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/198\/2016\/11\/23225424\/7-2-4.jpeg\" alt=\"This illustration shows a green ribbon, representing a folded membrane, with many folds stacked on top of another like a rope or hose. The photo shows an electron micrograph of a cleaved thylakoid membrane with similar folds from a unicellular organism\" width=\"500\" height=\"416\" \/><\/p>\n<p id=\"caption-attachment-1187\" class=\"wp-caption-text\">Figure 4. A photosynthetic prokaryote has infolded regions of the plasma membrane that function like thylakoids. Although these are not contained in an organelle, such as a chloroplast, all of the necessary components are present to carry out photosynthesis. (credit: scale-bar data from Matt Russell)<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"textbox learning-objectives\">\n<h3>In Summary: The Calvin Cycle<\/h3>\n<p>Using the energy carriers formed in the first stage of photosynthesis, the Calvin cycle reactions fix CO<sub>2<\/sub> from the environment to build carbohydrate molecules. An enzyme, RuBisCO, catalyzes the fixation reaction, by combining CO<sub>2<\/sub> with RuBP. The resulting six-carbon compound is broken down into two three-carbon compounds, and the energy in ATP and NADPH is used to convert these molecules into G3P. One of the three-carbon molecules of G3P leaves the cycle to become a part of a carbohydrate molecule. The remaining G3P molecules stay in the cycle to be formed back into RuBP, which is ready to react with more CO<sub>2<\/sub>. Photosynthesis forms a balanced energy cycle with the process of cellular respiration. Plants are capable of both photosynthesis and cellular respiration, since they contain both chloroplasts and mitochondria.<\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice Question<\/h3>\n<p>Which part of the Calvin cycle would be affected if a cell could not produce the enzyme RuBisCO?<\/p>\n<p><textarea aria-label=\"Your Answer\" rows=\"4\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q968396\">Show Answer<\/span><\/p>\n<div id=\"q968396\" class=\"hidden-answer\" style=\"display: none\">None of the cycle could take place, because RuBisCO is essential in fixing carbon dioxide. Specifically, RuBisCO catalyzes the reaction between carbon dioxide and RuBP at the start of the cycle.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_5d232a16-f62e-432e-b8a3-1020ad3de878\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/5d232a16-f62e-432e-b8a3-1020ad3de878?iframe_resize_id=assessment_practice_id_5d232a16-f62e-432e-b8a3-1020ad3de878\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-5012\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Concepts of Biology. <strong>Provided by<\/strong>: Open Stax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@9.25\">http:\/\/cnx.org\/contents\/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@9.25<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Download for free at http:\/\/cnx.org\/contents\/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@9.25<\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":18798,"menu_order":20,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Concepts of Biology\",\"author\":\"\",\"organization\":\"Open Stax\",\"url\":\"http:\/\/cnx.org\/contents\/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@9.25\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Download for free at http:\/\/cnx.org\/contents\/b3c1e1d2-839c-42b0-a314-e119a8aafbdd@9.25\"}]","CANDELA_OUTCOMES_GUID":"3bf6b690-c592-416b-bb61-53a8af8540a0, b7062e3e-51fd-4cb5-8d5a-ab250d1f7f62","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-5012","chapter","type-chapter","status-publish","hentry"],"part":168,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/5012","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/users\/18798"}],"version-history":[{"count":11,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/5012\/revisions"}],"predecessor-version":[{"id":6821,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/5012\/revisions\/6821"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/parts\/168"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/5012\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/media?parent=5012"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapter-type?post=5012"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/contributor?post=5012"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/license?post=5012"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}