{"id":240,"date":"2012-11-05T16:39:10","date_gmt":"2012-11-05T20:39:10","guid":{"rendered":"https:\/\/sites.owu.edu\/wolverton\/?page_id=240"},"modified":"2016-12-01T08:50:41","modified_gmt":"2016-12-01T13:50:41","slug":"dna","status":"publish","type":"page","link":"https:\/\/sites.owu.edu\/wolverton\/teaching\/cell-bio\/dna\/","title":{"rendered":"DNA"},"content":{"rendered":"<p><!--:en--><\/p>\n<h2 id=\"links\">Links<\/h2>\n<p><a href=\"http:\/\/www.nature.com\/principles\/ebooks\/introduction-to-cell-biology-4570805\/4570019\">Principles Module 46<\/a><\/p>\n<h2 id=\"objectives\">Objectives<\/h2>\n<ul>\n<li>Discuss the key experiments that demonstrated how we know that DNA is the heritable material<\/li>\n<\/ul>\n<h2 id=\"keypoints\">Key points<\/h2>\n<p>Morgan&#8217;s experiments on sex chromosomes demonstrated that genes were carried on chromosomes<\/p>\n<p>Griffith&#8217;s transformation experiment<\/p>\n<ul>\n<li>worked on pneumonia using mouse as a model system<\/li>\n<li>worked with 2 strains of bacteria, virulent (S) and nonvirulent \u00ae<\/li>\n<li>experiment<\/li>\n<ul>\n<li>inject with S strain, mice died<\/li>\n<li>inject with R strain, mice lived<\/li>\n<li>inject with heat-killed S strain, mice lived<\/li>\n<li>inject with heat-killed S strain mixed with R strain, mice died<\/li>\n<\/ul>\n<li>conclusion: something must be transferred from the dead S strain to the live R strain that <strong>transformed<\/strong> them into the S strain<\/li>\n<\/ul>\n<div>Avery, McLeod, and McCarty experiment<\/div>\n<div>\n<ul>\n<li>used the same model system as Griffith<\/li>\n<li>employed enzymes to digest either proteins, DNA, or RNA from the heat-killed S strain<\/li>\n<li>transformation was inhibited when DNA was digested, but not protein or RNA<\/li>\n<\/ul>\n<div>Hershey and Chase experiment<\/div>\n<div>\n<ul>\n<li>worked with bacteriophage virus (T2) that infects <em>E. coli<\/em>\u00a0cells<\/li>\n<li>this was a simplified model system because the virus only has protein and DNA<\/li>\n<li>knew that phages injected genetic material into host cell in order to replicate<\/li>\n<li>used radioactive P (in DNA) or S (in protein) to label molecules<\/li>\n<li>infected bacteria, removed the virus particles, identified the radiolabel<\/li>\n<li><em>E. coli<\/em>\u00a0cells contained radioactive P, not S, indicating that DNA was transferred from phage<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h2 id=\"in-classactivities\">In-class activities<\/h2>\n<h2 id=\"questionsforpractice\">Questions for Practice<\/h2>\n<ul>\n<li>In the Griffith experiment, what was the purpose of heating the S strain? Explain the result of mixing the killed S strain with the R strain.<\/li>\n<li>In the Avery experiment, why was the killed S strain treated with enzymes?<\/li>\n<li>What role did 35S and 32P play in the Hershey and Chase experiment?<\/li>\n<\/ul>\n<p><!--:--><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Links Principles Module 46 Objectives Discuss the key experiments that demonstrated how we know that DNA is the heritable material Key points Morgan&#8217;s experiments on sex chromosomes demonstrated that genes were carried on chromosomes Griffith&#8217;s transformation experiment worked on pneumonia using mouse as a model system worked with 2 strains of bacteria, virulent (S) and [&hellip;]<\/p>\n","protected":false},"author":40,"featured_media":0,"parent":447,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-240","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/users\/40"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/comments?post=240"}],"version-history":[{"count":1,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/240\/revisions"}],"predecessor-version":[{"id":498,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/240\/revisions\/498"}],"up":[{"embeddable":true,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/447"}],"wp:attachment":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/media?parent=240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}