Compare how pyruvate is used in human cells when oxygen is available and when oxygen is not available.

When oxygen is available- aerobic respiration takes place, when oxygen is not available- anaerobic respiration takes place. Pyruvate reacrs differently differently in these two situations.During Aerobic respiration- the pyruvate molecule enters the mitochondria whereas during anaerobic respiration the pyruvate molecule stays in the cytoplasm for further processing,Under Aerobic conditions the pyruvate is converted into the waste products of carbon dioxide and water, under anaerobic conditons the pyruvate is converted into the waste product of lactate.The ATP yield is significantly through the process of aerobic respiration, rather than through the use of anaerobic respiration which releases a small amount of ATP by comparison.