How does an animal cell reverse fermentation?

Animal cells do not reverse fermentation; instead, they utilize aerobic respiration when oxygen is available. During fermentation, cells convert glucose into energy anaerobically, producing byproducts like lactic acid. When oxygen becomes available, animal cells can metabolize lactic acid back into pyruvate, which then enters the mitochondria for aerobic respiration, allowing for more efficient energy production. Thus, the process shifts from anaerobic fermentation to aerobic pathways rather than reversing fermentation itself.