At the beginning of cellular respiration occurs, where glucose is broken down into pyruvate and ATP. This step does not require any oxygen. Therefore, glycolysis is done in BOTH aerobic and anaerobic respiration. The step of glycolysis generates ATP molecules. Glycolysis occurs in organisms.

You are in a weight-lifting program for one hour a day several days a week. During your workout, each exercise lasts only a minute or so because of how difficult the work is. A few hours after exercise, you notice that your muscles are sore and slightly swollen. Your muscle cells have experienced that led to the production of .

During aerobic cellular respiration, is used as the final electron acceptor.

But in anaerobic cellular respiration (fermentation), other molecules are used. The fermentation that occurs in our muscles uses as the final electron acceptor. Alcoholic fermentation uses ethanol as the final electron acceptor.

is a process that’s absent in cellular respiration in anaerobic organisms but present in aerobic organisms because it uses oxygen. However, is a process that doesn’t require oxygen so it can happen in organisms.