{"id":142,"date":"2012-11-05T11:39:48","date_gmt":"2012-11-05T15:39:48","guid":{"rendered":"https:\/\/sites.owu.edu\/wolverton\/?page_id=142"},"modified":"2016-12-01T08:50:41","modified_gmt":"2016-12-01T13:50:41","slug":"alternative-carbon-fixation","status":"publish","type":"page","link":"https:\/\/sites.owu.edu\/wolverton\/teaching\/cell-bio\/alternative-carbon-fixation\/","title":{"rendered":"Alternative Carbon Fixation"},"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\/4569872\">Principles Module 31<\/a><\/p>\n<h2 id=\"objectives\">Objectives<\/h2>\n<ul>\n<li>Distinguish between the two alternative pathways of carbon fixation<\/li>\n<li>Explain why these alternative pathways evolved (identify the selective pressures involved)<\/li>\n<\/ul>\n<h2 id=\"keypoints\">Key points<\/h2>\n<ul>\n<li>RuBisCO is an ancient enzyme, having evolved under an atmosphere without O<sub>2<\/sub>\n<ul>\n<li>it can accidentally bind to O<sub>2<\/sub> rather than CO<sub>2<\/sub> in the carboxylation reaction<\/li>\n<li>incorporation of an O<sub>2<\/sub> results in a waste product that is energetically expensive to recover<\/li>\n<\/ul>\n<\/li>\n<li>Some plants have evolved a carbon fixing step prior to the RuBisCO step that concentrates CO<sub>2<\/sub>for RuBisCO\n<ul>\n<li>C4 pathway plants have a carbon fixing step that is spatially separated from the pathway with RuBisCO<\/li>\n<li>CAM pathway plants have a carbon fixing step that is temporally separated from the pathway with RuBisCO<\/li>\n<li>both of these pathways incur greater \u2018costs\u2019 because they concentrate CO<sub>2<\/sub> for RuBisCO, but can also achieve greater rates of CO<sub>2<\/sub> fixation under certain conditions<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2 id=\"questionsforpractice\">Questions for Practice<\/h2>\n<ul>\n<li>Under what conditions does RuBisCO \u2018misfire\u2019 and incorporate an O<sub>2<\/sub> instead of a CO<sub>2<\/sub>? What is the result of this misfire?<\/li>\n<li>What benefit does oxygenation provide to the plant under these conditions?<\/li>\n<li>Compare and contrast C4 and CAM pathways.<\/li>\n<li>Why are C4 and CAM plants found in high-light environments? Why can\u2019t they grow well in shade?<\/li>\n<\/ul>\n<p><!--:--><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Links Principles Module 31 Objectives Distinguish between the two alternative pathways of carbon fixation Explain why these alternative pathways evolved (identify the selective pressures involved) Key points RuBisCO is an ancient enzyme, having evolved under an atmosphere without O2 it can accidentally bind to O2 rather than CO2 in the carboxylation reaction incorporation of an [&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-142","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/142","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=142"}],"version-history":[{"count":1,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/142\/revisions"}],"predecessor-version":[{"id":487,"href":"https:\/\/sites.owu.edu\/wolverton\/wp-json\/wp\/v2\/pages\/142\/revisions\/487"}],"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=142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}