In lactic acid fermentation, does glycolysis continue to generate ATP, and how?

• A. Yes, glycolysis continues as NAD+ is regenerated, but fermentation itself does not yield additional ATP
• B. No, glycolysis stops
• C. Fermentation directly yields large ATP amounts
• D. Fermentation depletes NAD+

Answer: (A)

Under anaerobic conditions, energy still comes mainly from glycolysis, which nets a small amount of ATP. To keep glycolysis running, NAD+ must be available. In lactic acid fermentation, pyruvate accepts electrons from NADH via lactate dehydrogenase, converting to lactate and regenerating NAD+. That regenerated NAD+ re-enters glycolysis, allowing another round of ATP production by substrate-level phosphorylation. The overall ATP yield still comes from glycolysis, giving about 2 ATP per glucose; the fermentation step itself does not produce much additional ATP.