In normal cellular respiration, ATP is created through glycolysis (cytoplasm), Krebs cycle (matrix) and the ETC (mitochondrial membrane).

During exercise however, aerobic (normal) cellular respiration gives way to anaerobic cellular respiration (fermentation):

In lactic acid fermentation, ATP is created through glycolysis (cytoplasm), and the fermentation to recycle materials also occurs in the cytoplasm.

Alcoholic fermentation occurs in yeasts

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