An athlete experiences muscle fatigue due to anaerobic metabolism during a sprint. Which process is responsible for the increased acidity in muscle cells?

💡 Explanation

Lactic acid fermentation regenerates NAD+ during anaerobic metabolism, which is necessary to sustain glycolysis. Because lactic acid is produced, this lowers the pH of the muscle cells, therefore accumulation of lactic acid leads to increased acidity, rather than other metabolic byproducts accumulating significantly.

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