∞ generated and posted on 2016.12.25 ∞
NADH- and CO2-generating step during cellular respiration that comes between glycolysis and the Krebs cycle and which produced acetyl CoA as an end product.
During pyruvate oxidation the three-carbon pyruvate is concerted to a two-carbon acetyl group, with the third carbon lost as carbon dioxide. The step is explicitly an oxidation reaction as two hydrogen atoms are stripped from pyruvate by NAD+. The acetyl group of acetyl CoA then enters the Krebs cycle by reacting with oxaloacetate (four carbons) to generate citric acid (six carbons).
Contrasting glycolysis, which take place in the cytosol of both prokaryotic and eukaryotic cells, pyruvate oxidation takes place in the mitochondria. As a consequence, all of the CO2 generated during cellular respiration are generated in the mitochondria. On the other hand, not all of the NADH are generated in the mitochondria since glycolysis also generates NADH and dose so external to the mitochondria in the cytosol.