Pyruvate decarboxylation

Overview
Pyruvate decarboxylation is the biochemical reaction that uses pyruvate to form acetyl-CoA, releasing reducing equivalents and carbon dioxide. Pyruvate decarboxylation, which links the metabolic pathways glycolysis and the citric acid cycle, is referred to as "the transition reaction," "the link reaction," or "the oxidative decarboxylation reaction." This reaction is usually catalyzed by the pyruvate dehydrogenase complex as part of aerobic respiration. In eukaryotes, pyruvate decarboxylation takes place exclusively inside mitochondria; in prokaryotes similar reactions take place in the cytoplasm and at the plasma membrane.

The oxidative decarboxylation of pyruvate in anaerobic organisms differs from the aerobic process in that the electron acceptor is an iron-sulfur protein, not NAD+. The conversion is catalyzed by a thiamine-dependent enzyme that also acylates coenzyme A. The reducing equivalents are disposed of by the production of H2 via hydrogenase.