{"id":117,"date":"2017-08-16T09:05:06","date_gmt":"2017-08-16T09:05:06","guid":{"rendered":"http:\/\/americanboard.org\/Subjects\/biology\/?page_id=117"},"modified":"2017-08-17T09:43:56","modified_gmt":"2017-08-17T09:43:56","slug":"nucleotides-and-nucleic-acids","status":"publish","type":"page","link":"https:\/\/americanboard.org\/Subjects\/biology\/nucleotides-and-nucleic-acids\/","title":{"rendered":"Nucleotides and Nucleic Acids"},"content":{"rendered":"<div class=\"twelve columns\" style=\"margin-top: 10%;\">\n<div class=\"advance\"><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/proteins\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/biochemical-basis-of-life\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/further-reading-2\">Further Reading \u27a1<\/a><\/div>\n<p><!-- CONTENT BEGINS HERE --><\/p>\n<h1 id=\"title\">Nucleotides and Nucleic Acids<\/h1>\n<h4>Objective<\/h4>\n<p>In this lesson, you will review nucleotides and nucleic acids.<\/p>\n<h4>Previously covered:<\/h4>\n<ul>\n<li>The genetic blueprint for life, DNA, codes for production of proteins.<\/li>\n<li>Proteins are complex organic molecules formed by peptide bonding of 20 unique amino acid monomers.<\/li>\n<\/ul>\n<section>\n<h3>Instruction Manual of Life<\/h3>\n<p><img decoding=\"async\" class=\"padding u-pull-right\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/BioMod31.3_DNARNA.jpg\" alt=\"DNA and RNA\" \/><\/p>\n<p>The nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), carry the instructions for the structure and function of all living things. Those instructions are stored in the cell nucleus and passed from generation to generation via DNA. The DNA instructions are carried by the RNA to the appropriate site, usually a ribosome, and used to build proteins as determined by the original DNA. It is thought that life began when a strand of RNA became incorporated in a cell membrane with proteins.<\/p>\n<p><abbr title=\"nucleic acid monomers formed when a nitrogen base is bonded to a phosphate group and a five carbon (pentose) sugar\">Nucleotide monomers<\/abbr> contain a five-carbon sugar called a pentose, one or more phosphate groups, and a nitrogenous base. The pentose sugar of RNA is ribose; its counterpart in DNA is deoxyribose. When nucleotide monomers form phosphodiester bonds the phosphate of one monomer bonds to the sugar of another, forming the backbone of the nucleic acid molecules.<\/p>\n<p>Each monomer contains one of five <abbr title=\"single or double ring structures providing connection by bonding to sugars Nitrogenous bases form a system of simple, dependable bonds that support the structure of DNA\">nitrogenous bases<\/abbr>. They are classified as either <abbr title=\"a type of nitrogenous base of which thymine is found in DNA; uridine in RNA; and cytosine in both\">pyrimidines<\/abbr> or <abbr title=\"a type of nitrogenous base; the purine bases in DNA and RNA are adenine and guanine\">purines<\/abbr>. The three pyrimidines\u2014cytosine, thymine, and uracil\u2014are single-ring structures. The purines\u2014guanine and adenine\u2014are double-ring structures. Adenine, guanine, and cytosine all occur in both DNA and RNA molecules. Thymine is unique to DNA and uracil is unique to RNA.<\/p>\n<p><center><img decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/pyrimidinepurine.jpg\" alt=\"Nitrogenous bases - adenine, thymine, guanine, cytosine\" \/><\/center><\/p>\n<p>RNA is a single-stranded molecule, while DNA is double-stranded. The double-stranded structure of DNA comes from hydrogen bonding between pyrimidines and purines. The hydrogen bonded nitrogen bases form the rungs of the DNA double helix ladder. In DNA, adenine always forms two hydrogen bonds with thymine, and cytosine always forms three hydrogen bonds with guanine. In RNA, uracil pairs with adenine. No other hydrogen bonding configuration between bases is possible.<\/p>\n<p><center><img decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/hydrogenbonds.jpg\" alt=\"Hydrogen bonds between G-C pairs and A-T pairs\" \/><\/center><\/p>\n<p><img decoding=\"async\" class=\"padding u-pull-right\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/BioMod31.3_doublehelix.jpg\" alt=\"DNA structure\" \/><\/p>\n<p>The double helix of DNA is composed of a coding strand and a template strand. The cell uses the template strand in the nucleus to build complementary strands of RNA. Single-stranded RNA carries the code in complementary bases to the site of protein production in the cell cytoplasm.<\/p>\n<p><img decoding=\"async\" class=\"padding u-pull-left\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/RNA.jpg\" alt=\"Sugar phosphate spine\" \/><\/p>\n<p>Other organic molecules are important in cell metabolism and in enzyme regulation. Several nucleotides (NAD and NADP) are important coenzymes in photosynthesis and respiration. Many are important in substrate level phosphorylation reactions.<\/p>\n<p>Adenosine triphosphate (ATP) is the form of energy cells use to do work. ATP is the form of energy plants produce during the light reactions of photosynthesis. It is the form of energy released during cellular respiration. Each ATP molecule is composed of a ribose, adenine, and a chain of three phosphate molecules. Because the phosphates have a negative electrical charge, they tend to repel each other. It takes energy to maintain those bonds; when they are broken, energy is released.<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/biology\/wp-content\/uploads\/sites\/2\/2017\/08\/BioMod31.3_threephosphate.jpg\" alt=\"Phosphates\" \/><\/p>\n<p>When the endmost oxygen-phosphate bond is broken, energy is released, and adenosine diphosphate (ADP) and a free phosphate are produced. Cells use energy to form the bonds in ATP and release it when those bonds are broken. By continuously cycling ADP and ATP, cells efficiently transform energy.<\/p>\n<section class=\"question\">\n<h4>Question<\/h4>\n<p>How does DNA differ from RNA?<\/p>\n<ol>\n<li>DNA is single-stranded while RNA is double-stranded.<\/li>\n<li>DNA contains the base thymine while RNA contains uracil.<\/li>\n<li>DNA contains ribose and RNA contains deoxyribose.<\/li>\n<li>DNA is formed by hydrogen bonds and RNA is formed by phosphodiester bonds.<\/li>\n<\/ol>\n<p><a class=\"q-answer button button-primary\">Reveal Answer<\/a><\/p>\n<p class=\"q-reveal\">B is the correct answer, because DNA is double-stranded, contains deoxyribose, and has plenty of phosphodiester bonds. RNA is single-stranded and contains ribose.<\/p>\n<\/section>\n<h3>Summary<\/h3>\n<ul>\n<li>Nucleotide monomers form complex organic molecules, such as nucleic acids, coenzymes, and ATP.<\/li>\n<li>DNA is a double-stranded helix of nucleotide monomers. The backbone of the helix is formed by and the rungs are formed by hydrogen bonds between complementary bases.<\/li>\n<li>RNA is a single-stranded molecule that is built of complementary bases to a DNA molecule.<\/li>\n<li>Other nucleotides, such as ATP and NAD+, are important in energy transformations in cells.<\/li>\n<\/ul>\n<\/section>\n<p><!-- CONTENT ENDS HERE --><\/p>\n<div class=\"advance\"><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/proteins\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/biochemical-basis-of-life\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/biology\/further-reading-2\">Further Reading \u27a1<\/a><\/div>\n<p><a class=\"backtotop\" href=\"#title\">Back to Top<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u2b05 Previous Lesson\u00a0Workshop Index\u00a0Further Reading \u27a1 Nucleotides and Nucleic Acids Objective In this lesson, you will review nucleotides and nucleic acids. Previously covered: The genetic blueprint for life, DNA, codes for production of proteins. Proteins are complex organic molecules formed by peptide bonding of 20 unique amino acid monomers. Instruction Manual of Life The nucleic [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-117","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/pages\/117","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/comments?post=117"}],"version-history":[{"count":7,"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/pages\/117\/revisions"}],"predecessor-version":[{"id":616,"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/pages\/117\/revisions\/616"}],"wp:attachment":[{"href":"https:\/\/americanboard.org\/Subjects\/biology\/wp-json\/wp\/v2\/media?parent=117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}