Biology 3593B Study Guide - Quiz Guide: Malate Dehydrogenase, Succinyl-Coa, Pyruvate Dehydrogenase
Document Summary
The tricarboxylic acid cycle (also known as the krebs cycle or the citric acid cycle) is the source of most of the atp generated in metabolism and the second stage of cellular respiration. A series of reactions occur in the mitochondria of eukaryotic cells resulting in the formation of atp and precursors for anabolic processes and reducing factors (fadh2 and nadh) which drive the production of even more atp. The citric acid cycle is an amphibolic pathway (a biochemical pathway that involves both catabolism and anabolism which together make up metabolism. ) 1. the cycle begins when acetyl coenzyme a, derived from the decarboxylation of pyruvate using the enzyme pyruvate dehydrogenase, reacts with oxaloacetate (a four-carbon molecule. ) This reaction forms citrate, a symmetrical six-carbon molecule, in an exergonic irreversible reaction catalysed by citrate synthase. Coa is then removed and returns to the glycolysis pathway: citrate is then converted into its isomer isocitrate.
