{"id":2530,"date":"2016-06-02T17:30:34","date_gmt":"2016-06-02T17:30:34","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/biologyxwaymakerxmaster\/?post_type=chapter&#038;p=2530"},"modified":"2024-04-26T00:26:53","modified_gmt":"2024-04-26T00:26:53","slug":"reading-major-enzymes","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/chapter\/reading-major-enzymes\/","title":{"raw":"Major Enzymes","rendered":"Major Enzymes"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Identify the major enzymes that play a role in DNA replication<\/li>\r\n<\/ul>\r\n<\/div>\r\nThe process of <strong>DNA replication<\/strong> is catalyzed by a type of enzyme called <strong>DNA polymerase<\/strong> (<em class=\"italic\">poly<\/em> meaning many, <em class=\"italic\">mer<\/em> meaning pieces, and -<em class=\"italic\">ase<\/em> meaning enzyme; so an enzyme that attaches many pieces of DNA). During replication, the two DNA strands separate at multiple points along the length of the chromosome. These locations are called origins of replication because replication begins at these points. Observe Figure\u00a01: the double helix of the original DNA molecule separates (blue) and new strands are made to match the separated strands. The result will be two DNA molecules, each containing an old and a new strand. Therefore, DNA replication is called semiconservative. The term <em class=\"bold\">semiconservative<\/em> refers to the fact that half of the original molecule (one of the two strands in the double helix) is \u201cconserved\u201d in the new molecule. The original strand is referred to as the <em class=\"bold\">template strand<\/em> because it provides the information, or template, for the newly synthesized strand.\r\n\r\n[caption id=\"attachment_2570\" align=\"aligncenter\" width=\"1024\"]<img class=\"wp-image-2570 size-large\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172248\/DNA_replication_split_horizontal.svg_-1024x508.png\" alt=\"Stylized DNA replication fork with nucleotides matched, 5'-&gt;3' synthesis shown, no enzymes in diagram. \" width=\"1024\" height=\"508\" \/> Figure\u00a01. By Madprime(wikipedia) (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:DNA_replication_split_horizontal.svg?uselang=en\" target=\"_blank\" rel=\"noopener\">DNA replication split horizontal<\/a>) CC BY-SA 2.0[\/caption]\r\n\r\n[caption id=\"attachment_2571\" align=\"alignright\" width=\"470\"]<img class=\"wp-image-2571 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172346\/RNA.jpg\" alt=\"Diagram of a primer moving along the template strand of DNA.\" width=\"470\" height=\"214\" \/> Figure\u00a02. Primer and Template[\/caption]\r\n\r\n<strong>DNA polymerase<\/strong> needs an \u201canchor\u201d to start adding nucleotides: a short sequence of DNA or RNA that is complementary to the template strand will work to provide a free 3\u2032 end. This sequence is called a <em>primer\u00a0<\/em>(Figure\u00a02).\r\n\r\nHow does <strong>DNA polymerase<\/strong> know in what order to add nucleotides? Specific base pairing in DNA is the key to copying the DNA: if you know the sequence of one strand, you can use base pairing rules to build the other strand. Bases form pairs (base pairs) in a very specific way.\r\n\r\n[caption id=\"attachment_2572\" align=\"aligncenter\" width=\"451\"]<img class=\"wp-image-2572\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172431\/Molecular-DNA.png\" alt=\"Diagram showing the hydrogen bonds between nucleotides. Adenine is bound to thymine, and cytosine is bound to guanine. \" width=\"451\" height=\"312\" \/> Figure\u00a03. DNA chemical structure. Modification of <a href=\"https:\/\/en.wikipedia.org\/wiki\/File:DNA_chemical_structure.svg\" target=\"_blank\" rel=\"noopener\">DNA chemical structure<\/a>\u00a0by Madeleine Price Ball; CC-BY-SA-2.0[\/caption]\r\n\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Questions<\/h3>\r\nTrue\/False: DNA replication requires an enzyme.\r\n\r\n[practice-area rows=\"1\"][\/practice-area]\r\n[reveal-answer q=\"527189\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"527189\"]True.\u00a0Most biological reactions rely on the enzyme to speed up the reaction. In the case of DNA\u00a0replication, this enzyme is DNA polymerase.\r\n\r\n[\/hidden-answer]\r\n\r\nWhat are the building blocks on DNA?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>Deoxyribonucleotides<\/li>\r\n \t<li>Fatty acids<\/li>\r\n \t<li>Ribonucleotides<\/li>\r\n \t<li>Amino acids<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"93495\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"93495\"]Answer a. DNA is a double helix made up of two long chains of deoxyribonucleotides.\r\n\r\n[\/hidden-answer]\r\n\r\nTrue\/False: DNA replication requires energy.\r\n\r\n[practice-area rows=\"1\"][\/practice-area]\r\n[reveal-answer q=\"62103\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"62103\"]True.\u00a0Making large molecules from small subunits (anabolism) requires energy. What supplies the\u00a0energy? The building blocks themselves serve as a source of energy. As they get incorporated into\u00a0the DNA polymer, two phosphate groups are broken off to release energy, some of which is used for\u00a0making the polymer. Deoxyribonucleotides differ from nucleotides like ATP only by one missing oxygen atom.\r\n\r\n[\/hidden-answer]\r\n\r\nWe have the building blocks, a source of energy, and a catalyst. What's missing? We need instruction about the order of nucleotides in the new polymer. Which molecule provides these instructions?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>Protein<\/li>\r\n \t<li>DNA<\/li>\r\n \t<li>Carbohydrate<\/li>\r\n \t<li>Lipid<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"494506\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"494506\"]Answer b.\u00a0We refer to this DNA as a template. The original information stored in the order of bases will\u00a0direct the synthesis of the new DNA via base pairing.\r\n\r\n[\/hidden-answer]\r\n\r\nThere is one more thing required by the DNA polymerase. It cannot just start making a DNA copy of the template strand; it needs a short piece of DNA or RNA with a free hydroxyl group in the right place to attach the nucleotides to. (Remember that synthesis always occurs in one direction\u2014new building blocks are added to the 3\u2032 end.) This component starts the process by giving DNA polymerase something to bind to. What might you call this short piece of nucleic acid?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>A solvent<\/li>\r\n \t<li>A primer<\/li>\r\n \t<li>A converter<\/li>\r\n \t<li>A sealant<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"529681\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"529681\"]Answer b. A primer is used to start this process by giving DNA polymerase something to bind the new nucleotide to.[\/hidden-answer]\r\n\r\n<\/div>\r\nNow that you understand the basics of <strong>DNA replication<\/strong>, we can add a bit of complexity. The two strands of\u00a0DNA have to be temporarily separated from each other; this job is done by a special enzyme, <strong><em>helicase<\/em><\/strong>, that helps unwind and separate the DNA helices (Figure\u00a04). Another issue is that the DNA polymerase only works in one direction along the strand (5\u2032 to 3\u2032), but the double-stranded DNA has two strands oriented in opposite directions. This problem is solved by synthesizing the two strands slightly differently: one new strand grows continuously, the other in bits and pieces. The leading strand grows continuously and the lagging strand is put together with short pieces called Okazaki fragments. These fragments are connected and linked together by an enzyme called DNA ligase. Short fragments of RNA are used as primers for the DNA polymerase.\r\n\r\n[caption id=\"attachment_2573\" align=\"aligncenter\" width=\"1024\"]<img class=\"wp-image-2573 size-large\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172842\/DNA_replication_en.svg_-1024x498.png\" alt=\"Diagram of both the leading and lagging strands the helicase splits the two strands and a DNA polymerase travels over both strands to create complementary strands.\" width=\"1024\" height=\"498\" \/> Figure\u00a04. By Mariana Ruiz (<a href=\"https:\/\/en.wikipedia.org\/wiki\/File:DNA_replication_en.svg\" target=\"_blank\" rel=\"noopener\">DNA replication<\/a>) Public Domain[\/caption]\r\n\r\n<div class=\"textbox exercises\">\r\n<h3>Practice Questions<\/h3>\r\nWhich of these separates the two complementary strands of DNA?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>DNA polymerase<\/li>\r\n \t<li>helicase<\/li>\r\n \t<li>RNA primer<\/li>\r\n \t<li>single-strand binding protein<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"197431\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"197431\"]Answer b. Helicase breaks the hydrogen bonds holding together the two strands of DNA.\r\n\r\n[\/hidden-answer]\r\n\r\nWhich of these attaches complementary bases to the template strand?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>DNA polymerase<\/li>\r\n \t<li>helicase<\/li>\r\n \t<li>RNA primer<\/li>\r\n \t<li>single-strand binding protein<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"381621\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"381621\"]Answer a. DNA polymerase builds the new strand of DNA.\r\n\r\n[\/hidden-answer]\r\n\r\nWhich of these is later replaced with DNA bases?\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n \t<li>DNA polymerase<\/li>\r\n \t<li>helicase<\/li>\r\n \t<li>RNA primer<\/li>\r\n \t<li>single-strand binding protein<\/li>\r\n<\/ol>\r\n[reveal-answer q=\"2143\"]Show Answers[\/reveal-answer]\r\n[hidden-answer a=\"2143\"]Answer c. the RNA primer is replaced with DNA nucleotides.[\/hidden-answer]\r\n\r\n<\/div>\r\n<iframe src=\"https:\/\/lumenlearning.h5p.com\/content\/1291213467038110188\/embed\" width=\"1088\" height=\"637\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><script src=\"https:\/\/lumenlearning.h5p.com\/js\/h5p-resizer.js\" charset=\"UTF-8\"><\/script>\r\n<div class=\"textbox learning-objectives\">\r\n<h3>In Summary: Major Enzymes<\/h3>\r\nReplication in eukaryotes starts at multiple origins of replication. A primer is required to initiate synthesis, which is then extended by DNA polymerase as it adds nucleotides one by one to the growing chain. The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short stretches called Okazaki fragments. The RNA primers are replaced with DNA nucleotides; the DNA remains one continuous strand by linking the DNA fragments with DNA ligase.\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/54578131-3414-496e-b20b-37ca90d03322\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Identify the major enzymes that play a role in DNA replication<\/li>\n<\/ul>\n<\/div>\n<p>The process of <strong>DNA replication<\/strong> is catalyzed by a type of enzyme called <strong>DNA polymerase<\/strong> (<em class=\"italic\">poly<\/em> meaning many, <em class=\"italic\">mer<\/em> meaning pieces, and &#8211;<em class=\"italic\">ase<\/em> meaning enzyme; so an enzyme that attaches many pieces of DNA). During replication, the two DNA strands separate at multiple points along the length of the chromosome. These locations are called origins of replication because replication begins at these points. Observe Figure\u00a01: the double helix of the original DNA molecule separates (blue) and new strands are made to match the separated strands. The result will be two DNA molecules, each containing an old and a new strand. Therefore, DNA replication is called semiconservative. The term <em class=\"bold\">semiconservative<\/em> refers to the fact that half of the original molecule (one of the two strands in the double helix) is \u201cconserved\u201d in the new molecule. The original strand is referred to as the <em class=\"bold\">template strand<\/em> because it provides the information, or template, for the newly synthesized strand.<\/p>\n<div id=\"attachment_2570\" style=\"width: 1034px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2570\" class=\"wp-image-2570 size-large\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172248\/DNA_replication_split_horizontal.svg_-1024x508.png\" alt=\"Stylized DNA replication fork with nucleotides matched, 5'-&gt;3' synthesis shown, no enzymes in diagram.\" width=\"1024\" height=\"508\" \/><\/p>\n<p id=\"caption-attachment-2570\" class=\"wp-caption-text\">Figure\u00a01. By Madprime(wikipedia) (<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:DNA_replication_split_horizontal.svg?uselang=en\" target=\"_blank\" rel=\"noopener\">DNA replication split horizontal<\/a>) CC BY-SA 2.0<\/p>\n<\/div>\n<div id=\"attachment_2571\" style=\"width: 480px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2571\" class=\"wp-image-2571 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172346\/RNA.jpg\" alt=\"Diagram of a primer moving along the template strand of DNA.\" width=\"470\" height=\"214\" \/><\/p>\n<p id=\"caption-attachment-2571\" class=\"wp-caption-text\">Figure\u00a02. Primer and Template<\/p>\n<\/div>\n<p><strong>DNA polymerase<\/strong> needs an \u201canchor\u201d to start adding nucleotides: a short sequence of DNA or RNA that is complementary to the template strand will work to provide a free 3\u2032 end. This sequence is called a <em>primer\u00a0<\/em>(Figure\u00a02).<\/p>\n<p>How does <strong>DNA polymerase<\/strong> know in what order to add nucleotides? Specific base pairing in DNA is the key to copying the DNA: if you know the sequence of one strand, you can use base pairing rules to build the other strand. Bases form pairs (base pairs) in a very specific way.<\/p>\n<div id=\"attachment_2572\" style=\"width: 461px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2572\" class=\"wp-image-2572\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172431\/Molecular-DNA.png\" alt=\"Diagram showing the hydrogen bonds between nucleotides. Adenine is bound to thymine, and cytosine is bound to guanine.\" width=\"451\" height=\"312\" \/><\/p>\n<p id=\"caption-attachment-2572\" class=\"wp-caption-text\">Figure\u00a03. DNA chemical structure. Modification of <a href=\"https:\/\/en.wikipedia.org\/wiki\/File:DNA_chemical_structure.svg\" target=\"_blank\" rel=\"noopener\">DNA chemical structure<\/a>\u00a0by Madeleine Price Ball; CC-BY-SA-2.0<\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice Questions<\/h3>\n<p>True\/False: DNA replication requires an enzyme.<\/p>\n<p><textarea aria-label=\"Your Answer\" rows=\"1\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q527189\">Show Answer<\/span><\/p>\n<div id=\"q527189\" class=\"hidden-answer\" style=\"display: none\">True.\u00a0Most biological reactions rely on the enzyme to speed up the reaction. In the case of DNA\u00a0replication, this enzyme is DNA polymerase.<\/p>\n<\/div>\n<\/div>\n<p>What are the building blocks on DNA?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>Deoxyribonucleotides<\/li>\n<li>Fatty acids<\/li>\n<li>Ribonucleotides<\/li>\n<li>Amino acids<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q93495\">Show Answer<\/span><\/p>\n<div id=\"q93495\" class=\"hidden-answer\" style=\"display: none\">Answer a. DNA is a double helix made up of two long chains of deoxyribonucleotides.<\/p>\n<\/div>\n<\/div>\n<p>True\/False: DNA replication requires energy.<\/p>\n<p><textarea aria-label=\"Your Answer\" rows=\"1\"><\/textarea><\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q62103\">Show Answer<\/span><\/p>\n<div id=\"q62103\" class=\"hidden-answer\" style=\"display: none\">True.\u00a0Making large molecules from small subunits (anabolism) requires energy. What supplies the\u00a0energy? The building blocks themselves serve as a source of energy. As they get incorporated into\u00a0the DNA polymer, two phosphate groups are broken off to release energy, some of which is used for\u00a0making the polymer. Deoxyribonucleotides differ from nucleotides like ATP only by one missing oxygen atom.<\/p>\n<\/div>\n<\/div>\n<p>We have the building blocks, a source of energy, and a catalyst. What&#8217;s missing? We need instruction about the order of nucleotides in the new polymer. Which molecule provides these instructions?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>Protein<\/li>\n<li>DNA<\/li>\n<li>Carbohydrate<\/li>\n<li>Lipid<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q494506\">Show Answer<\/span><\/p>\n<div id=\"q494506\" class=\"hidden-answer\" style=\"display: none\">Answer b.\u00a0We refer to this DNA as a template. The original information stored in the order of bases will\u00a0direct the synthesis of the new DNA via base pairing.<\/p>\n<\/div>\n<\/div>\n<p>There is one more thing required by the DNA polymerase. It cannot just start making a DNA copy of the template strand; it needs a short piece of DNA or RNA with a free hydroxyl group in the right place to attach the nucleotides to. (Remember that synthesis always occurs in one direction\u2014new building blocks are added to the 3\u2032 end.) This component starts the process by giving DNA polymerase something to bind to. What might you call this short piece of nucleic acid?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>A solvent<\/li>\n<li>A primer<\/li>\n<li>A converter<\/li>\n<li>A sealant<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q529681\">Show Answer<\/span><\/p>\n<div id=\"q529681\" class=\"hidden-answer\" style=\"display: none\">Answer b. A primer is used to start this process by giving DNA polymerase something to bind the new nucleotide to.<\/div>\n<\/div>\n<\/div>\n<p>Now that you understand the basics of <strong>DNA replication<\/strong>, we can add a bit of complexity. The two strands of\u00a0DNA have to be temporarily separated from each other; this job is done by a special enzyme, <strong><em>helicase<\/em><\/strong>, that helps unwind and separate the DNA helices (Figure\u00a04). Another issue is that the DNA polymerase only works in one direction along the strand (5\u2032 to 3\u2032), but the double-stranded DNA has two strands oriented in opposite directions. This problem is solved by synthesizing the two strands slightly differently: one new strand grows continuously, the other in bits and pieces. The leading strand grows continuously and the lagging strand is put together with short pieces called Okazaki fragments. These fragments are connected and linked together by an enzyme called DNA ligase. Short fragments of RNA are used as primers for the DNA polymerase.<\/p>\n<div id=\"attachment_2573\" style=\"width: 1034px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2573\" class=\"wp-image-2573 size-large\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/110\/2016\/06\/02172842\/DNA_replication_en.svg_-1024x498.png\" alt=\"Diagram of both the leading and lagging strands the helicase splits the two strands and a DNA polymerase travels over both strands to create complementary strands.\" width=\"1024\" height=\"498\" \/><\/p>\n<p id=\"caption-attachment-2573\" class=\"wp-caption-text\">Figure\u00a04. By Mariana Ruiz (<a href=\"https:\/\/en.wikipedia.org\/wiki\/File:DNA_replication_en.svg\" target=\"_blank\" rel=\"noopener\">DNA replication<\/a>) Public Domain<\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice Questions<\/h3>\n<p>Which of these separates the two complementary strands of DNA?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>DNA polymerase<\/li>\n<li>helicase<\/li>\n<li>RNA primer<\/li>\n<li>single-strand binding protein<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q197431\">Show Answer<\/span><\/p>\n<div id=\"q197431\" class=\"hidden-answer\" style=\"display: none\">Answer b. Helicase breaks the hydrogen bonds holding together the two strands of DNA.<\/p>\n<\/div>\n<\/div>\n<p>Which of these attaches complementary bases to the template strand?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>DNA polymerase<\/li>\n<li>helicase<\/li>\n<li>RNA primer<\/li>\n<li>single-strand binding protein<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q381621\">Show Answer<\/span><\/p>\n<div id=\"q381621\" class=\"hidden-answer\" style=\"display: none\">Answer a. DNA polymerase builds the new strand of DNA.<\/p>\n<\/div>\n<\/div>\n<p>Which of these is later replaced with DNA bases?<\/p>\n<ol style=\"list-style-type: lower-alpha;\">\n<li>DNA polymerase<\/li>\n<li>helicase<\/li>\n<li>RNA primer<\/li>\n<li>single-strand binding protein<\/li>\n<\/ol>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q2143\">Show Answers<\/span><\/p>\n<div id=\"q2143\" class=\"hidden-answer\" style=\"display: none\">Answer c. the RNA primer is replaced with DNA nucleotides.<\/div>\n<\/div>\n<\/div>\n<p><iframe loading=\"lazy\" src=\"https:\/\/lumenlearning.h5p.com\/content\/1291213467038110188\/embed\" width=\"1088\" height=\"637\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><script src=\"https:\/\/lumenlearning.h5p.com\/js\/h5p-resizer.js\" charset=\"UTF-8\"><\/script><\/p>\n<div class=\"textbox learning-objectives\">\n<h3>In Summary: Major Enzymes<\/h3>\n<p>Replication in eukaryotes starts at multiple origins of replication. A primer is required to initiate synthesis, which is then extended by DNA polymerase as it adds nucleotides one by one to the growing chain. The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short stretches called Okazaki fragments. The RNA primers are replaced with DNA nucleotides; the DNA remains one continuous strand by linking the DNA fragments with DNA ligase.<\/p>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_54578131-3414-496e-b20b-37ca90d03322\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/54578131-3414-496e-b20b-37ca90d03322?iframe_resize_id=assessment_practice_id_54578131-3414-496e-b20b-37ca90d03322\" 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-2530\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Revision, adaptation, and original content. <strong>Authored by<\/strong>: Shelli Carter and Lumen Learning. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>DNA Replication. <strong>Provided by<\/strong>: Open Learning Initiative. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f7e80020ca6000225da6a4220c9\">https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f7e80020ca6000225da6a4220c9<\/a>. <strong>Project<\/strong>: Introduction to Biology (Open + Free). <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em><\/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":7,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"DNA Replication\",\"author\":\"\",\"organization\":\"Open Learning Initiative\",\"url\":\"https:\/\/oli.cmu.edu\/jcourse\/workbook\/activity\/page?context=434a5f7e80020ca6000225da6a4220c9\",\"project\":\"Introduction to Biology (Open + Free)\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"\"},{\"type\":\"original\",\"description\":\"Revision, adaptation, and original content\",\"author\":\"Shelli Carter and Lumen Learning\",\"organization\":\"Lumen Learning\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"1fbd08f9-207b-44b9-88af-fe1b331ed80e, 98ea2694-2611-4580-bb14-876f83051cfe","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2530","chapter","type-chapter","status-publish","hentry"],"part":297,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2530","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\/17"}],"version-history":[{"count":30,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2530\/revisions"}],"predecessor-version":[{"id":6767,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2530\/revisions\/6767"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/parts\/297"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapters\/2530\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/media?parent=2530"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/pressbooks\/v2\/chapter-type?post=2530"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/contributor?post=2530"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-nmbiology1\/wp-json\/wp\/v2\/license?post=2530"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}