Final answer:
Fermentation is necessary for energy production in the absence of oxygen. It allows glycolysis to continue and produce ATP. However, the ATP yield of fermentation is lower compared to aerobic metabolism.
Step-by-step explanation:
Fermentation is necessary for energy production in the absence of oxygen.
During fermentation, organisms use alternative electron acceptors to ensure the continuation of glycolysis and the production of ATP.
Without fermentation, glycolysis would not occur and no ATP would be harvested from the breakdown of glucose.
Comparing the ATP yield, aerobic metabolism (cellular respiration) can yield 36-38 ATP molecules, while anaerobic metabolism (fermentation) only produces 2 ATP molecules through substrate-level phosphorylation during glycolysis.
Therefore, fermentation has a lower ATP yield compared to aerobic metabolism.