Under low oxygen conditions, what is the end product of anaerobic glycolysis?

Under low oxygen conditions, what is the end product of anaerobic glycolysis?

• A. Acetyl-CoA
• B. Lactic acid
• C. CO2
• D. Water

Answer: (B)

When oxygen is scarce, glycolysis can still run, but NAD+ must be regenerated to keep the pathway turning. This happens when pyruvate accepts electrons from NADH to form lactate, a reaction catalyzed by lactate dehydrogenase. Regenerating NAD+ allows glycolysis to continue and produce a small amount of ATP, though no further aerobic pathways can proceed. The end product in this anaerobic state is lactic acid (lactate). Acetyl-CoA forms in the presence of oxygen via the pyruvate dehydrogenase step and feeds the Krebs cycle, CO2 is mainly produced in the aerobic decarboxylation steps, and water is produced during oxidative phosphorylation, not directly in anaerobic glycolysis. So lactic acid is the correct end product under low oxygen.

When oxygen is scarce, glycolysis can still run, but NAD+ must be regenerated to keep the pathway turning. This happens when pyruvate accepts electrons from NADH to form lactate, a reaction catalyzed by lactate dehydrogenase. Regenerating NAD+ allows glycolysis to continue and produce a small amount of ATP, though no further aerobic pathways can proceed. The end product in this anaerobic state is lactic acid (lactate). Acetyl-CoA forms in the presence of oxygen via the pyruvate dehydrogenase step and feeds the Krebs cycle, CO2 is mainly produced in the aerobic decarboxylation steps, and water is produced during oxidative phosphorylation, not directly in anaerobic glycolysis. So lactic acid is the correct end product under low oxygen.