Fermentation is anaerobic and produces lactate or ethanol.

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Multiple Choice

Fermentation is anaerobic and produces lactate or ethanol.

Fermentation is an anaerobic pathway that regenerates NAD+ so glycolysis can keep producing ATP when oxygen is scarce. In the absence of oxygen, cells can’t efficiently run the mitochondrial electron transport chain, so they rely on fermentation to reoxidize NADH to NAD+. This process yields lactate in animals (and some bacteria) or ethanol and CO2 in yeast and other microorganisms. Because it uses glycolysis plus a short fermentation step, the net ATP gain is only about 2 ATP per glucose, far less than aerobic respiration. It happens in the cytosol, not in mitochondria. So describing fermentation as anaerobic and producing lactate or ethanol accurately reflects its key features.

Fermentation is an anaerobic pathway that regenerates NAD+ so glycolysis can keep producing ATP when oxygen is scarce. In the absence of oxygen, cells can’t efficiently run the mitochondrial electron transport chain, so they rely on fermentation to reoxidize NADH to NAD+. This process yields lactate in animals (and some bacteria) or ethanol and CO2 in yeast and other microorganisms. Because it uses glycolysis plus a short fermentation step, the net ATP gain is only about 2 ATP per glucose, far less than aerobic respiration. It happens in the cytosol, not in mitochondria. So describing fermentation as anaerobic and producing lactate or ethanol accurately reflects its key features.

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