Anaerobic respiration is an enzyme-controlled, partial break down of organic compounds (food) without using oxygen and releasing only a fraction of the energy. It is also called intra-molecular respiration. The respiration results in incomplete degradation of the substrate to CO2 and organic compounds like ethyl alcohol, lactic acid etc. accompanied by the release of some energy. A number of ATP molecules evolved in one complete cycle of anaerobic respiration is 2.