BY 108 Chapter Notes - Chapter 9: Pyruvate Dehydrogenase, Citric Acid Cycle, Decarboxylation
Document Summary
Occurs in only in mitochondria of eukaryotes. 1st forms acetyl-coa from pyruvate, then oxidizes acetyl-coa in krebs cycle. Single decarboxylation reaction that cleaves off one of the carbons on pyruvate (producing acetyl group and co2) Pyruvate dehydrogenase - enzyme that removes co2 from pyruvate; has 60 subunits. Pyruvate + nad+ + coa (coenzyme a) >> acetyle-coa + nadh + co2. Acetyl-coa - produced by a large number of metabolic processes. Key point for many catabolic processes in eukaryotes. Used for fatty acid synthesis instead of krebs cycle when atp levels are high. Krebs cycle - stage 3 takes place in mitochondria matrix. Combines acetyle-coa (2-carbon molecule) w/ oxaloacetate (4-carbon molecule) to extract electrons and co2 to power proton pumps for atp. Step a - priming; 3 reactions rearrange chemical groups in acetyl-coa to prepare the 6-carbon molecule for energy extraction. Step b - energy extraction; 4/6 reactions oxidize and remove electrons.
