Summary
Highlights
Pyruvate oxidation is the second step of aerobic respiration, following glycolysis. In glycolysis, glucose is converted into two molecules of pyruvate. These pyruvate molecules then enter the mitochondria for pyruvate oxidation.
Inside the mitochondria, pyruvate is converted into acetyl-CoA. This acetyl-CoA then proceeds to the Krebs cycle. The process involves the release of carbon dioxide and the action of the enzyme pyruvate dehydrogenase.
Pyruvate dehydrogenase removes hydrogen from coenzyme A, which then attaches to NAD+ to form NADH. Coenzyme A then attaches to the carbon of pyruvate, forming acetyl-CoA. Two molecules of carbon dioxide are released in this step, one for each pyruvate molecule.
The two-carbon acetyl-CoA molecule is now ready to enter the Krebs cycle (also known as the citric acid cycle), where its carbon atoms will be released as carbon dioxide. In total, six carbon dioxide molecules are released from one glucose molecule during aerobic respiration. The energy carriers NADH and FADH2 then enter the electron transport chain to produce ATP, with oxygen acting as the final electron acceptor to form water.