Citrate Synthase: Difference between revisions

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==The Structure and Mechanism of Citrate Synthase==

Citrate synthase is an enzyme active in all examined cells, where it is most often responsible for catalyzing the first reaction of the [[The Citric Acid Cycle|citric acid cycle (Krebs Cycle or the tricarboxylic acid <nowiki>[</nowiki>TCA<nowiki>]</nowiki> cycle)]]: the condensation of acetyl-CoA and oxaloacetate to form citrate. Although in eukaryotes it is a mitochondrial enzyme, and in fact, is often used as a enzyme marker for intact mitochondria, it is encoded by nuclear DNA<ref>[http://en.wikipedia.org/wiki/Citrate_synthase "Citrate Synthase -." Wikipedia, the Free Encyclopedia. Web. 22 Mar. 2010].</ref>. The standard free energy change (ΔG°’) for the citrate synthase reaction is

'''Citrate synthase''' is an enzyme active in all examined cells, where it is most often responsible for catalyzing the first reaction of the [[The Citric Acid Cycle|citric acid cycle (Krebs Cycle or the tricarboxylic acid <nowiki>[</nowiki>TCA<nowiki>]</nowiki> cycle)]]: the condensation of acetyl-CoA and oxaloacetate to form citrate. Although in eukaryotes it is a mitochondrial enzyme, and in fact, is often used as a enzyme marker for intact mitochondria, it is encoded by nuclear DNA<ref>[http://en.wikipedia.org/wiki/Citrate_synthase "Citrate Synthase -." Wikipedia, the Free Encyclopedia. Web. 22 Mar. 2010].</ref>. The standard free energy change (ΔG°’) for the citrate synthase reaction is

-31.5kJ/mol <ref name="voet">Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry: Life at the Molecular Level. Hoboken, NJ: Wiley, 2008.</ref>. This negative free energy value means that citrate synthase is likely to function far from equilibrium under physiological conditions, and is thus a rate-determining enzyme in the citric acid cycle.

Citrate Synthase: Difference between revisions

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 ==The Structure and Mechanism of Citrate Synthase==
 <Structure load='1cts' size='480' frame='true' align='right' scene='User:Wayne_Decatur/1cts_to_2cts_(citrate_synthase)_morph_methods/Camorph/5' caption='Citrate Synthase' />
-Citrate synthase is an enzyme active in all examined cells, where it is most often responsible for catalyzing the first reaction of the [[The Citric Acid Cycle|citric acid cycle (Krebs Cycle or the tricarboxylic acid <nowiki>[</nowiki>TCA<nowiki>]</nowiki> cycle)]]: the condensation of acetyl-CoA and oxaloacetate to form citrate.  Although in eukaryotes it is a mitochondrial enzyme, and in fact, is often used as a enzyme marker for intact mitochondria, it is encoded by nuclear DNA<ref>[http://en.wikipedia.org/wiki/Citrate_synthase "Citrate Synthase -." Wikipedia, the Free Encyclopedia. Web. 22 Mar. 2010].</ref>. The standard free energy change (ΔG°’) for the citrate synthase reaction is
+'''Citrate synthase''' is an enzyme active in all examined cells, where it is most often responsible for catalyzing the first reaction of the [[The Citric Acid Cycle|citric acid cycle (Krebs Cycle or the tricarboxylic acid <nowiki>[</nowiki>TCA<nowiki>]</nowiki> cycle)]]: the condensation of acetyl-CoA and oxaloacetate to form citrate.  Although in eukaryotes it is a mitochondrial enzyme, and in fact, is often used as a enzyme marker for intact mitochondria, it is encoded by nuclear DNA<ref>[http://en.wikipedia.org/wiki/Citrate_synthase "Citrate Synthase -." Wikipedia, the Free Encyclopedia. Web. 22 Mar. 2010].</ref>. The standard free energy change (ΔG°’) for the citrate synthase reaction is
 -31.5kJ/mol <ref name="voet">Voet, Donald, Judith G. Voet, and Charlotte W. Pratt. Fundamentals of Biochemistry: Life at the Molecular Level. Hoboken, NJ: Wiley, 2008.</ref>. This negative free energy value means that citrate synthase is likely to function far from equilibrium under physiological conditions, and is thus a rate-determining enzyme in the citric acid cycle.