What is the fate of pyruvic acid in aerobic respiration?
What is the fate of pyruvic acid in aerobic respiration?
Answered
In aerobic respiration, the fate of pyruvic acid (pyruvate) is closely tied to its entry into the mitochondria. After glucose is metabolized through glycolysis in the cytoplasm, pyruvate is produced. Under aerobic conditions (presence of oxygen), pyruvate is transported into the mitochondria where it undergoes decarboxylation by the enzyme pyruvate dehydrogenase. This results in the production of acetyl-CoA, a two-carbon molecule that enters the citric acid cycle (Krebs cycle). During this process, pyruvate is also decarboxylated (losing a carbon atom as carbon dioxide) and oxidized, generating NADH from NAD+. Acetyl-CoA then combines with oxaloacetate to form citrate in the first step of the citric acid cycle, where it undergoes further reactions to produce ATP, NADH, FADH2, and CO2. These products are critical for ATP generation in oxidative phosphorylation.