Which pathway is anaerobic and produces lactic acid or ethanol plus CO2, producing little ATP?

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Multiple Choice

Which pathway is anaerobic and produces lactic acid or ethanol plus CO2, producing little ATP?

This item tests an anaerobic energy pathway that regenerates NAD+ to keep glycolysis going and ends with products like lactate or ethanol plus CO2. Fermentation fits because, in the absence of oxygen, cells convert pyruvate into lactate (in lactic acid fermentation) or into ethanol and carbon dioxide (in alcoholic fermentation). This process regenerates NAD+ from NADH, allowing glycolysis to continue and supply a small amount of ATP (2 ATP per glucose), since fermentation itself doesn’t produce much additional energy. Glycolysis occurs with or without oxygen and provides pyruvate, but the production of lactic acid or ethanol plus CO2 is specifically the hallmark of fermentation. Cellular respiration and photosynthesis involve different pathways and end products (aerobic ATP production with CO2 and H2O, or sugar synthesis from CO2 and water, respectively) and do not describe this fermentation fate.

This item tests an anaerobic energy pathway that regenerates NAD+ to keep glycolysis going and ends with products like lactate or ethanol plus CO2. Fermentation fits because, in the absence of oxygen, cells convert pyruvate into lactate (in lactic acid fermentation) or into ethanol and carbon dioxide (in alcoholic fermentation). This process regenerates NAD+ from NADH, allowing glycolysis to continue and supply a small amount of ATP (2 ATP per glucose), since fermentation itself doesn’t produce much additional energy.

Glycolysis occurs with or without oxygen and provides pyruvate, but the production of lactic acid or ethanol plus CO2 is specifically the hallmark of fermentation. Cellular respiration and photosynthesis involve different pathways and end products (aerobic ATP production with CO2 and H2O, or sugar synthesis from CO2 and water, respectively) and do not describe this fermentation fate.

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