{"id":139,"date":"2017-02-04T20:34:17","date_gmt":"2017-02-05T03:34:17","guid":{"rendered":"https:\/\/blogs.ubc.ca\/mrpletsch\/?p=139"},"modified":"2019-01-23T18:46:39","modified_gmt":"2019-01-24T01:46:39","slug":"dna-structure","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/mrpletsch\/2017\/02\/04\/dna-structure\/","title":{"rendered":"2.6 DNA Structure"},"content":{"rendered":"<p><strong>2.6.U1 &#8211; The nucleic acids DNA and RNA are polymers of nucleotides<\/strong><\/p>\n<ul>\n<li>Linear molecules that stores biological information in units known as nucleotides.<\/li>\n<li>4 nucleotide base pairs make up the DNA \u201calphabet\u201d<\/li>\n<\/ul>\n<p>G \u2013 Guanine C \u2013 Cytosine A \u2013 Adenine T \u2013 Thymine<\/p>\n<figure id=\"attachment_140\" aria-describedby=\"caption-attachment-140\" style=\"width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-140\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/DNAstruc-300x230.png\" alt=\"\" width=\"300\" height=\"230\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/DNAstruc-300x230.png 300w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/DNAstruc-552x423.png 552w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/DNAstruc.png 642w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-140\" class=\"wp-caption-text\">Figure 1: DNA nucleotide structure<\/figcaption><\/figure>\n<ul>\n<li>This nucleotide code specifies <strong>which <\/strong>protein an organism will make.<\/li>\n<li>DNA molecule is a <strong>double strand<\/strong> of nucleotides carrying <u>complimentary<\/u> base pairs.<\/li>\n<\/ul>\n<p><strong>DNA Nucleotide &#8211;<\/strong> 3 components: a phosphate group (PO<sub>4<\/sub>), a pentose (5) sugar, and a nitrogenous base.<\/p>\n<p>Each DNA Nucleotide = <strong>monomer<\/strong>, the DNA strand = <strong>polymer<\/strong><\/p>\n<p style=\"margin-left: 7.1pt;\"><strong>2.6.U3 -DNA is a double helix made of two antiparallel strands of nucleotides linked by hydrogen bonding between base pairs<\/strong><\/p>\n<p><strong>Antiparallel = <\/strong>Parallel but moving or oriented in opposite directions.<\/p>\n<p><span style=\"text-decoration: underline;\"><strong>RULES FOR BASE PAIRING:<\/strong><\/span><\/p>\n<p>C with G: The <strong>pyramidine <\/strong>Cytosine always pairs with the <strong>purine<\/strong> Guanine<\/p>\n<p>A with T: The <strong>pyramidine<\/strong> Thymine always pairs with the <strong>purine<\/strong> Adenine<\/p>\n<figure id=\"attachment_141\" aria-describedby=\"caption-attachment-141\" style=\"width: 280px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-141 size-medium\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc2-280x300.png\" width=\"280\" height=\"300\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc2-280x300.png 280w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc2.png 532w\" sizes=\"auto, (max-width: 280px) 100vw, 280px\" \/><figcaption id=\"caption-attachment-141\" class=\"wp-caption-text\">Figure 2: DNA complimentary base pairing<\/figcaption><\/figure>\n<p><strong>Question: <\/strong><em>Why can\u2019t A pair with C and G with T?<\/em><\/p>\n<p><em>Only with A &amp; T and with C &amp; G are there opportunities to establish <strong>hydrogen bonds based on molecular structure.<\/strong> (Two between A and T and three between C and G)<\/em><\/p>\n<p>The rules of base pairing tell us that if we can &#8220;read&#8221; the sequence of nucleotides on one strand of DNA, we can immediately deduce the complementary sequence on the other strand.<\/p>\n<table>\n<tbody>\n<tr>\n<td width=\"221\">\n<p><strong>Pyramidine:<\/strong><\/p>\n<p>A pyrimidine is a heterocyclic organic compound<\/p>\n<p>&#8211;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Two nitrogen atoms.<\/p>\n<p>&#8211;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 One carbon ring<\/p>\n<p><strong>\u00a0<\/strong><\/td>\n<td width=\"221\">\n<p><strong>Purine:<\/strong><\/p>\n<p>A purine is a heterocyclic organic compound<\/p>\n<p>&#8211;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Four nitrogen atoms.<\/p>\n<p>&#8211;\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Two carbon ring<\/p>\n<p><strong>\u00a0<\/strong><\/td>\n<\/tr>\n<tr>\n<td width=\"221\">\n<p><figure id=\"attachment_142\" aria-describedby=\"caption-attachment-142\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-142\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc3-300x129.png\" alt=\"\" width=\"300\" height=\"129\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc3-300x129.png 300w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruc3.png 482w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-142\" class=\"wp-caption-text\">Figure 3: Pyramidines<\/figcaption><\/figure><\/td>\n<td width=\"221\">\n<p><figure id=\"attachment_143\" aria-describedby=\"caption-attachment-143\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-143\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct4-300x119.png\" alt=\"\" width=\"300\" height=\"119\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct4-300x119.png 300w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct4.png 525w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-143\" class=\"wp-caption-text\">Figure 4: Purines<\/figcaption><\/figure><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li>DNA is double stranded. Each strand is composed of nucleotides where the <u>pentose sugar <\/u>of one nucleotide is covalently bonded to the phosphate group of the next.<\/li>\n<\/ul>\n<ul>\n<li>The two strands are parallel, but are oriented in opposite directions. The stands are held together by hydrogen bonding between <u>complimentary base pairs.<\/u><\/li>\n<\/ul>\n<p><strong>2.6.U2 &#8211; DNA differs from RNA in the number of strands present, the base composition and the type of pentose<\/strong><\/p>\n<table>\n<tbody>\n<tr>\n<td width=\"221\"><strong>DNA<\/strong><\/td>\n<td width=\"221\"><strong>RNA<\/strong><\/td>\n<\/tr>\n<tr>\n<td width=\"221\">Sugar is <strong>deoxyribose<\/strong> (carbon 2 &#8211; no oxygen attached)<\/td>\n<td width=\"221\">Sugar is <strong>ribose<\/strong> (carbon 2 has an \u2013OH attached)<\/td>\n<\/tr>\n<tr>\n<td width=\"221\">Nitrogenous bases are guanine, adenine, cytosine and <strong><em>thymine<\/em><\/strong><\/td>\n<td width=\"221\">Nitrogenous bases are guanine, adenine, cytosine and <strong><em>uracil<\/em><\/strong><\/td>\n<\/tr>\n<tr>\n<td width=\"221\"><strong>Double-stranded<\/strong> molecule<\/td>\n<td width=\"221\"><strong>Single-stranded<\/strong> molecule<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>Source: http:\/\/ibworld.me\/Biochemistry.html#2.7_DNA_structure<\/em><\/p>\n<figure id=\"attachment_144\" aria-describedby=\"caption-attachment-144\" style=\"width: 300px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-144\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct5-300x195.png\" alt=\"\" width=\"300\" height=\"195\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct5-300x195.png 300w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct5-552x359.png 552w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct5.png 609w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-144\" class=\"wp-caption-text\">Figure 5: Differences between DNA and RNA nucleotides<\/figcaption><\/figure>\n<p><strong>Ribose,<\/strong> found in RNA, is a &#8220;normal&#8221; sugar, with one oxygen atom attached to each carbon atom.<\/p>\n<p><strong>Deoxyribose,<\/strong> found in DNA, is a modified sugar, lacking one oxygen atom at the <strong>second <\/strong>carbon. This difference of one oxygen atom is important for the enzymes that recognize DNA and RNA, because it allows these two molecules to be easily distinguished inside organisms.<\/p>\n<p><strong><u>DNA Directionality \u2013 Understanding 5\u2019 and 3\u2019<\/u><\/strong><\/p>\n<figure id=\"attachment_145\" aria-describedby=\"caption-attachment-145\" style=\"width: 252px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-145\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct6-252x300.png\" alt=\"\" width=\"252\" height=\"300\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct6-252x300.png 252w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct6.png 344w\" sizes=\"auto, (max-width: 252px) 100vw, 252px\" \/><figcaption id=\"caption-attachment-145\" class=\"wp-caption-text\">Figure 6: Nucleotide numbering<\/figcaption><\/figure>\n<p>Numbering the carbons matter!<\/p>\n<p>&nbsp;<\/p>\n<p>Since, the DNA stands are <strong>anti-parallel<\/strong>, we expect each strand to have a 5\u2019 end <strong>opposite of each other. <\/strong>Likewise with the 3\u2019 end.<\/p>\n<figure id=\"attachment_146\" aria-describedby=\"caption-attachment-146\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-146\" src=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct7-300x235.png\" alt=\"\" width=\"300\" height=\"235\" srcset=\"https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct7-300x235.png 300w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct7-552x433.png 552w, https:\/\/blogs.ubc.ca\/mrpletsch\/files\/2017\/02\/dnastruct7.png 620w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-146\" class=\"wp-caption-text\">Figure 7: DNA directionality<\/figcaption><\/figure>\n<p><strong><a href=\"https:\/\/www.youtube.com\/watch?v=p835L4HWH68\">Directionality of DNA [Video]<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p class=\"post-excerpt\">2.6.U1 &#8211; The nucleic acids DNA and RNA are polymers of nucleotides Linear molecules that stores biological information in units&#8230;<\/p>\n","protected":false},"author":48401,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2064941],"tags":[],"class_list":["post-139","post","type-post","status-publish","format-standard","hentry","category-ib-biology"],"_links":{"self":[{"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/posts\/139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/users\/48401"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/comments?post=139"}],"version-history":[{"count":3,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/posts\/139\/revisions"}],"predecessor-version":[{"id":550,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/posts\/139\/revisions\/550"}],"wp:attachment":[{"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/media?parent=139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/categories?post=139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/mrpletsch\/wp-json\/wp\/v2\/tags?post=139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}