As the name suggests, aerobic respiration uses oxygen, while anaerobic respiration does not. Oxygen is the electron acceptor in aerobic respiration, while in anaerobic respiration other species such as Fe(III), Nitrate (NO3-), sulfate (SO4 2-), carbon dioxide, etc. are used as electron acceptor. The presence of oxygen as electron acceptor means that aerobic reactions are always more energy generating than anaerobic respiration reactions. In fact, aerobic respiration generates 36-38 molecules of energy (ATP or adenosine triphosphate), whereas the anaerobic respiration generates lesser number of ATP molecules (between 2-36). Aerobic respiration results in complete oxidation of food, while anaerobic respiration does not. Most of the higher life forms, such as animal, human beings, etc. uses aerobic respiration, while single celled organisms (or prokaryotes) use anaerobic respiration.
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