What is the ATP yield of fermentation?

Fermentation is an anaerobic process that occurs when oxygen is not available for cellular respiration. In fermentation, glucose is partially broken down to produce ATP, but it is much less efficient than aerobic respiration. During this process, the glycolysis pathway is activated, which generates a net gain of 2 ATP molecules per glucose molecule. This is because glycolysis produces 4 ATP but consumes 2 ATP in the conversion of glucose to pyruvate, leading to a net yield of 2.

Unlike aerobic respiration, which can yield up to 38 ATP molecules by fully oxidizing glucose through the Krebs cycle and oxidative phosphorylation, fermentation does not utilize these pathways. Instead, it generates a limited amount of ATP alongside byproducts like lactic acid or ethanol. Hence, the ATP yield of fermentation is correctly identified as 2 ATP molecules per glucose.