Link reaction or Acetylation of Pyruvate:
Pyruvic acid undergoes oxidative decarboxylation before entering Krebs cycle.
Removal of carbon dioxide along with oxidation by removal of hydrogen takes place.
The reaction is catalyzed by enzyme pyruvic dehydrogenase (oxidase).
Co-enzyme NAD and co-enzyme -A, are required for this reaction.
Pyruvic acid (3C) undergoes decarboxylation first and then oxidation by removal of H, which is taken up by NAD and NADH, is formed.
Acetyl fraction (2C) that remains after decarboxylation is taken up by co-enzyme A and Acetyl Co-A is formed. This is called Acetylation of Pyruvate.
Glycolysis ends with the formation of pyruvate and food enters as acetyl co-A in the Krebs cycle.
Therefore, formation of acetyl Co-A or acetylation of pyruvate is called connecting link between glycolysis and Krebs cycle or Link reaction.
Pyruvate is converted to acetyl coenzyme-A in the perimitochondrial space.
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