{"id":3369,"date":"2016-11-16T18:23:47","date_gmt":"2016-11-16T18:23:47","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/wm-biology1\/?post_type=chapter&#038;p=3369"},"modified":"2024-04-26T22:27:08","modified_gmt":"2024-04-26T22:27:08","slug":"reading-signaling-in-bacteria","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-biology1\/chapter\/reading-signaling-in-bacteria\/","title":{"raw":"Signaling in Bacteria","rendered":"Signaling in Bacteria"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Relate the role of quorum sensing to the ability of some bacteria to form biofilms<\/li>\r\n<\/ul>\r\n<\/div>\r\nSignaling in bacteria enables bacteria to monitor extracellular conditions, ensure that there are sufficient amounts of nutrients, and ensure that hazardous situations are avoided. There are circumstances, however, when bacteria communicate with each other.\r\n\r\nThe first evidence of bacterial communication was observed in a bacterium that has a symbiotic relationship with Hawaiian bobtail squid. When the population density of the bacteria reaches a certain level, specific gene expression is initiated, and the bacteria produce bioluminescent proteins that emit light. Because the number of cells present in the environment (cell density) is the determining factor for signaling, bacterial signaling was named <strong>quorum sensing<\/strong>. In politics and business, a quorum is the minimum number of members required to be present to vote on an issue.\r\n\r\nQuorum sensing uses autoinducers as signaling molecules. <strong>Autoinducers<\/strong> are signaling molecules secreted by bacteria to communicate with other bacteria of the same kind. The secreted autoinducers can be small, hydrophobic molecules such as acyl-homoserine lactone, (AHL) or larger peptide-based molecules; each type of molecule has a different mode of action. When AHL enters target bacteria, it binds to transcription factors, which then switch gene expression on or off (see Figure\u00a01). The peptide autoinducers stimulate more complicated signaling pathways that include bacterial kinases. The changes in bacteria following exposure to autoinducers can be quite extensive. The pathogenic bacterium <em>Pseudomonas aeruginosa<\/em> has 616 different genes that respond to autoinducers.\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Question<\/h3>\r\n[caption id=\"attachment_3372\" align=\"aligncenter\" width=\"725\"]<img class=\"wp-image-3372 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1087\/2016\/11\/16181223\/Figure_09_04_02.png\" alt=\"The left part of this illustration shows a single bacterial cell. The cell produces autoinducers, which diffuse away from the cell and cannot bind the intracellular receptor. The right part of this illustration shows many bacterial cells. More autoinducers are present, which bind receptors that in turn bind DNA and regulate the expression of certain genes. Autoinducer gene expression is turned on, resulting in a positive-feedback loop.\" width=\"725\" height=\"895\" \/> Figure 1. Autoinducers are small molecules or proteins produced by bacteria that regulate gene expression.[\/caption]\r\n\r\nWhich of the following statements about quorum sensing is false?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>Autoinducer must bind to receptor to turn on transcription of genes responsible for the production of more autoinducer.<\/li>\r\n \t<li>The receptor stays in the bacterial cell, but the autoinducer diffuses out.<\/li>\r\n \t<li>Autoinducer can only act on a different cell: it cannot act on the cell in which it is made.<\/li>\r\n \t<li>Autoinducer turns on genes that enable the bacteria to form a biofilm.<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"147760\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"147760\"]Answer c is false.[\/hidden-answer]\r\n\r\n<\/div>\r\nSome species of bacteria that use quorum sensing form biofilms, complex colonies of bacteria (often containing several species) that exchange chemical signals to coordinate the release of toxins that will attack the host. Bacterial biofilms (Figure 2) can sometimes be found on medical equipment; when biofilms invade implants such as hip or knee replacements or heart pacemakers, they can cause life-threatening infections.\r\n\r\nCell-cell communication enables <em>Staphylococcus aureus<\/em> bacteria (Figure 2a) to work together to form a biofilm inside a hospital patient\u2019s catheter, seen here via scanning electron microscopy. <em>S. aureus<\/em> is the main cause of hospital-acquired infections. Hawaiian bobtail squid (Figure 2b) have a symbiotic relationship with the bioluminescent bacteria <em>Vibrio fischeri<\/em>. The luminescence makes it difficult to see the squid from below because it effectively eliminates its shadow. In return for camouflage, the squid provides food for the bacteria. Free-living <em>V. fischeri<\/em> do not produce luciferase, the enzyme responsible for luminescence, but <em>V. fischeri<\/em> living in a symbiotic relationship with the squid do. Quorum sensing determines whether the bacteria should produce the luciferase enzyme.\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Question<\/h3>\r\n[caption id=\"attachment_3373\" align=\"aligncenter\" width=\"725\"]<img class=\"wp-image-3373 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1087\/2016\/11\/16181523\/Figure_09_04_03.png\" alt=\"Part a: This electron micrograph shows a film of bacteria. Part b: This photo shows a Hawaiian bobtail squid.\" width=\"725\" height=\"316\" \/> Figure 2. (a) Staphylococcus aureus bacteria. (b) Hawaiian bobtail squid. (credit a: modifications of work by CDC\/Janice Carr; credit b: modifications of work by Cliff1066\/Flickr)[\/caption]\r\n\r\nWhat advantage might biofilm production confer on the <em data-effect=\"italics\">S. aureus<\/em> inside the catheter?\r\n\r\n[practice-area rows=\"2\"][\/practice-area]\r\n[reveal-answer q=\"10146\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"10146\"]<em>S. aureus<\/em> produces a biofilm because the higher cell density in the biofilm permits the formation of a dense surface that helps protect the bacteria from antibiotics.[\/hidden-answer]\r\n\r\n<\/div>\r\nResearch on the details of quorum sensing has led to advances in growing bacteria for industrial purposes. Recent discoveries suggest that it may be possible to exploit bacterial signaling pathways to control bacterial growth; this process could replace or supplement antibiotics that are no longer effective in certain situations.\r\n<div class=\"textbox shaded\">\r\n\r\nWatch geneticist Bonnie Bassler discuss her discovery of quorum sensing in biofilm bacteria in squid.\r\n\r\n<iframe src=\"\/\/plugin.3playmedia.com\/show?mf=4409363&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=573&amp;video_id=KXWurAmtf78&amp;video_target=tpm-plugin-up893h6v-KXWurAmtf78\" width=\"800px\" height=\"500px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe>\r\n\r\nYou can <a href=\"https:\/\/course-building.s3-us-west-2.amazonaws.com\/Biology+for+Majors+I\/Transcriptions\/HowBacteriaTalkBonnieBassler_Transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for \"How Bacteria 'Talk' \" here (link opens in new window)<\/a>.\r\n\r\n<\/div>\r\n<div class=\"textbox shaded\">\r\n\r\nWatch this collection of interview clips with biofilm researchers in \u201cWhat Are Bacterial Biofilms?\u201d\r\n\r\n<iframe src=\"\/\/plugin.3playmedia.com\/show?mf=4409364&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=573&amp;video_id=lpI4WCM_9pM&amp;video_target=tpm-plugin-o3peui6z-lpI4WCM_9pM\" width=\"800px\" height=\"500px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe>\r\n\r\nYou can <a href=\"https:\/\/course-building.s3-us-west-2.amazonaws.com\/Biology+for+Majors+I\/Transcriptions\/WhatareBacterialBiofilms_Transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for \"What are Bacterial Biofilms? A Six Minute Montage\" here (link opens in new window)<\/a>.\r\n\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Questions<\/h3>\r\n<p id=\"fs-id2914757\">Quorum sensing is triggered to begin when ___________.<\/p>\r\n\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>treatment with antibiotics occurs<\/li>\r\n \t<li>bacteria release growth hormones<\/li>\r\n \t<li>bacterial protein expression is switched on<\/li>\r\n \t<li>a sufficient number of bacteria are present<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"578321\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"578321\"]Answer d. Quorum sensing is triggered to begin when a sufficient number of bacteria are present.\r\n\r\n[\/hidden-answer]\r\n\r\nWhy is signaling in multicellular organisms more complicated than signaling in single-celled organisms?\r\n\r\n[practice-area rows=\"2\"][\/practice-area]\r\n[reveal-answer q=\"43987\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"43987\"]Multicellular organisms must coordinate many different events in different cell types that may be very distant from each other. Single-celled organisms are only concerned with their immediate environment and the presence of other cells in the area.[\/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\/238bf30f-6c35-44dd-b475-2f60c6cdbc9f\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Relate the role of quorum sensing to the ability of some bacteria to form biofilms<\/li>\n<\/ul>\n<\/div>\n<p>Signaling in bacteria enables bacteria to monitor extracellular conditions, ensure that there are sufficient amounts of nutrients, and ensure that hazardous situations are avoided. There are circumstances, however, when bacteria communicate with each other.<\/p>\n<p>The first evidence of bacterial communication was observed in a bacterium that has a symbiotic relationship with Hawaiian bobtail squid. When the population density of the bacteria reaches a certain level, specific gene expression is initiated, and the bacteria produce bioluminescent proteins that emit light. Because the number of cells present in the environment (cell density) is the determining factor for signaling, bacterial signaling was named <strong>quorum sensing<\/strong>. In politics and business, a quorum is the minimum number of members required to be present to vote on an issue.<\/p>\n<p>Quorum sensing uses autoinducers as signaling molecules. <strong>Autoinducers<\/strong> are signaling molecules secreted by bacteria to communicate with other bacteria of the same kind. The secreted autoinducers can be small, hydrophobic molecules such as acyl-homoserine lactone, (AHL) or larger peptide-based molecules; each type of molecule has a different mode of action. When AHL enters target bacteria, it binds to transcription factors, which then switch gene expression on or off (see Figure\u00a01). The peptide autoinducers stimulate more complicated signaling pathways that include bacterial kinases. The changes in bacteria following exposure to autoinducers can be quite extensive. The pathogenic bacterium <em>Pseudomonas aeruginosa<\/em> has 616 different genes that respond to autoinducers.<\/p>\n<div class=\"textbox exercises\">\n<h3>Practice Question<\/h3>\n<div id=\"attachment_3372\" style=\"width: 735px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3372\" class=\"wp-image-3372 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1087\/2016\/11\/16181223\/Figure_09_04_02.png\" alt=\"The left part of this illustration shows a single bacterial cell. The cell produces autoinducers, which diffuse away from the cell and cannot bind the intracellular receptor. The right part of this illustration shows many bacterial cells. More autoinducers are present, which bind receptors that in turn bind DNA and regulate the expression of certain genes. Autoinducer gene expression is turned on, resulting in a positive-feedback loop.\" width=\"725\" height=\"895\" \/><\/p>\n<p id=\"caption-attachment-3372\" class=\"wp-caption-text\">Figure 1. Autoinducers are small molecules or proteins produced by bacteria that regulate gene expression.<\/p>\n<\/div>\n<p>Which of the following statements about quorum sensing is false?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>Autoinducer must bind to receptor to turn on transcription of genes responsible for the production of more autoinducer.<\/li>\n<li>The receptor stays in the bacterial cell, but the autoinducer diffuses out.<\/li>\n<li>Autoinducer can only act on a different cell: it cannot act on the cell in which it is made.<\/li>\n<li>Autoinducer turns on genes that enable the bacteria to form a biofilm.<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q147760\">Show Answer<\/span><\/p>\n<div id=\"q147760\" class=\"hidden-answer\" style=\"display: none\">Answer c is false.<\/div>\n<\/div>\n<\/div>\n<p>Some species of bacteria that use quorum sensing form biofilms, complex colonies of bacteria (often containing several species) that exchange chemical signals to coordinate the release of toxins that will attack the host. Bacterial biofilms (Figure 2) can sometimes be found on medical equipment; when biofilms invade implants such as hip or knee replacements or heart pacemakers, they can cause life-threatening infections.<\/p>\n<p>Cell-cell communication enables <em>Staphylococcus aureus<\/em> bacteria (Figure 2a) to work together to form a biofilm inside a hospital patient\u2019s catheter, seen here via scanning electron microscopy. <em>S. aureus<\/em> is the main cause of hospital-acquired infections. Hawaiian bobtail squid (Figure 2b) have a symbiotic relationship with the bioluminescent bacteria <em>Vibrio fischeri<\/em>. The luminescence makes it difficult to see the squid from below because it effectively eliminates its shadow. In return for camouflage, the squid provides food for the bacteria. Free-living <em>V. fischeri<\/em> do not produce luciferase, the enzyme responsible for luminescence, but <em>V. fischeri<\/em> living in a symbiotic relationship with the squid do. Quorum sensing determines whether the bacteria should produce the luciferase enzyme.<\/p>\n<div class=\"textbox exercises\">\n<h3>Practice Question<\/h3>\n<div id=\"attachment_3373\" style=\"width: 735px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-3373\" class=\"wp-image-3373 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1087\/2016\/11\/16181523\/Figure_09_04_03.png\" alt=\"Part a: This electron micrograph shows a film of bacteria. Part b: This photo shows a Hawaiian bobtail squid.\" width=\"725\" height=\"316\" \/><\/p>\n<p id=\"caption-attachment-3373\" class=\"wp-caption-text\">Figure 2. (a) Staphylococcus aureus bacteria. (b) Hawaiian bobtail squid. (credit a: modifications of work by CDC\/Janice Carr; credit b: modifications of work by Cliff1066\/Flickr)<\/p>\n<\/div>\n<p>What advantage might biofilm production confer on the <em data-effect=\"italics\">S. aureus<\/em> inside the catheter?<\/p>\n<p><textarea aria-label=\"Your Answer\" rows=\"2\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q10146\">Show Answer<\/span><\/p>\n<div id=\"q10146\" class=\"hidden-answer\" style=\"display: none\"><em>S. aureus<\/em> produces a biofilm because the higher cell density in the biofilm permits the formation of a dense surface that helps protect the bacteria from antibiotics.<\/div>\n<\/div>\n<\/div>\n<p>Research on the details of quorum sensing has led to advances in growing bacteria for industrial purposes. Recent discoveries suggest that it may be possible to exploit bacterial signaling pathways to control bacterial growth; this process could replace or supplement antibiotics that are no longer effective in certain situations.<\/p>\n<div class=\"textbox shaded\">\n<p>Watch geneticist Bonnie Bassler discuss her discovery of quorum sensing in biofilm bacteria in squid.<\/p>\n<p><iframe loading=\"lazy\" src=\"\/\/plugin.3playmedia.com\/show?mf=4409363&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=573&amp;video_id=KXWurAmtf78&amp;video_target=tpm-plugin-up893h6v-KXWurAmtf78\" width=\"800px\" height=\"500px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe><\/p>\n<p>You can <a href=\"https:\/\/course-building.s3-us-west-2.amazonaws.com\/Biology+for+Majors+I\/Transcriptions\/HowBacteriaTalkBonnieBassler_Transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for &#8220;How Bacteria &#8216;Talk&#8217; &#8221; here (link opens in new window)<\/a>.<\/p>\n<\/div>\n<div class=\"textbox shaded\">\n<p>Watch this collection of interview clips with biofilm researchers in \u201cWhat Are Bacterial Biofilms?\u201d<\/p>\n<p><iframe loading=\"lazy\" src=\"\/\/plugin.3playmedia.com\/show?mf=4409364&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=573&amp;video_id=lpI4WCM_9pM&amp;video_target=tpm-plugin-o3peui6z-lpI4WCM_9pM\" width=\"800px\" height=\"500px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe><\/p>\n<p>You can <a href=\"https:\/\/course-building.s3-us-west-2.amazonaws.com\/Biology+for+Majors+I\/Transcriptions\/WhatareBacterialBiofilms_Transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for &#8220;What are Bacterial Biofilms? A Six Minute Montage&#8221; here (link opens in new window)<\/a>.<\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice Questions<\/h3>\n<p id=\"fs-id2914757\">Quorum sensing is triggered to begin when ___________.<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>treatment with antibiotics occurs<\/li>\n<li>bacteria release growth hormones<\/li>\n<li>bacterial protein expression is switched on<\/li>\n<li>a sufficient number of bacteria are present<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q578321\">Show Answer<\/span><\/p>\n<div id=\"q578321\" class=\"hidden-answer\" style=\"display: none\">Answer d. Quorum sensing is triggered to begin when a sufficient number of bacteria are present.<\/p>\n<\/div>\n<\/div>\n<p>Why is signaling in multicellular organisms more complicated than signaling in single-celled organisms?<\/p>\n<p><textarea aria-label=\"Your Answer\" rows=\"2\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q43987\">Show Answer<\/span><\/p>\n<div id=\"q43987\" class=\"hidden-answer\" style=\"display: none\">Multicellular organisms must coordinate many different events in different cell types that may be very distant from each other. Single-celled organisms are only concerned with their immediate environment and the presence of other cells in the area.<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_238bf30f-6c35-44dd-b475-2f60c6cdbc9f\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/238bf30f-6c35-44dd-b475-2f60c6cdbc9f?iframe_resize_id=assessment_practice_id_238bf30f-6c35-44dd-b475-2f60c6cdbc9f\" 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-3369\">\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>Biology 2e. <strong>Provided by<\/strong>: OpenStax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\">http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8<\/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>: Access for free at https:\/\/openstax.org\/books\/biology-2e\/pages\/1-introduction<\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">All rights reserved content<\/div><ul class=\"citation-list\"><li>How bacteria talk - Bonnie Bassler. <strong>Authored by<\/strong>: Bonnie Bassler. <strong>Provided by<\/strong>: TED-Ed. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/KXWurAmtf78\">https:\/\/youtu.be\/KXWurAmtf78<\/a>. <strong>License<\/strong>: <em>All Rights Reserved<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><li>What Are Bacterial Biofilms? A Six Minute Montage. <strong>Authored by<\/strong>: biofilm. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/lpI4WCM_9pM\">https:\/\/youtu.be\/lpI4WCM_9pM<\/a>. <strong>License<\/strong>: <em>All Rights Reserved<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/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":17,"menu_order":14,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Biology 2e\",\"author\":\"\",\"organization\":\"OpenStax\",\"url\":\"http:\/\/cnx.org\/contents\/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.8\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Access for free at https:\/\/openstax.org\/books\/biology-2e\/pages\/1-introduction\"},{\"type\":\"copyrighted_video\",\"description\":\"How bacteria talk - Bonnie Bassler\",\"author\":\"Bonnie Bassler\",\"organization\":\"TED-Ed\",\"url\":\"https:\/\/youtu.be\/KXWurAmtf78\",\"project\":\"\",\"license\":\"arr\",\"license_terms\":\"Standard YouTube License\"},{\"type\":\"copyrighted_video\",\"description\":\"What Are Bacterial Biofilms? A Six Minute Montage\",\"author\":\"biofilm\",\"organization\":\"\",\"url\":\"https:\/\/youtu.be\/lpI4WCM_9pM\",\"project\":\"\",\"license\":\"arr\",\"license_terms\":\"Standard YouTube License\"}]","CANDELA_OUTCOMES_GUID":"b8e512fc-d9d9-478c-8bc6-586bd761cf88, 44f87f72-8730-480c-b789-8a8eaeb4d954","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-3369","chapter","type-chapter","status-publish","hentry"],"part":3271,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/3369","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/users\/17"}],"version-history":[{"count":14,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/3369\/revisions"}],"predecessor-version":[{"id":5935,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/3369\/revisions\/5935"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/parts\/3271"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapters\/3369\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/media?parent=3369"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/pressbooks\/v2\/chapter-type?post=3369"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/contributor?post=3369"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-biology1\/wp-json\/wp\/v2\/license?post=3369"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}