The fate of pyruvate depends on the oxygen availability: - Aerobic Conditions: Pyruvate is transported into the mitochondria where it is converted into acetyl-CoA by the enzyme pyruvate dehydrogenase. Acetyl-CoA then enters the citric acid cycle. - Anaerobic Conditions: In the absence of oxygen, pyruvate undergoes fermentation to form lactate in animals (lactic acid fermentation) or ethanol in yeast (alcoholic fermentation).
