There are two types of respiration. Aerobic respiration and Anaerobic respiration. In aerobic respiration oxygen is necessary for respiration but it Anaerobic respiration, oxygen is not necessary for respiration. Aerobic respiration produces 15 times more energy than the anaerobic respiration. The advantage of aerobic respiration over anaerobic respiration is, therefore, quiet evident. That is why you see that large organisms have aerobic respiration. But anaerobic respiration is also important in its place because of the following reasons:
(1) The planet of earth in its early time had an environment which was totally devoid of oxygen. The aerobic organisms can not exist in anaerobic environment.
(2) Some existing organisms, like bacteria and parasites which live in oxygen environment, have anaerobic respiration and many useful bacteria and yeast are anaerobic.
(3) Even in the aerobic respiration, the first phase is anaerobic. The glycolysis which is the first phase of carbohydrate metabolism involves reaction which do not require the expedition of molecular oxygen. This may in a way support the notion that aerobic organisms have evolved from the anaerobic organisms.
(4) In some active tissues like skeletal muscles, although aerobic metabolism takes place but in sustained activity when the oxygen supply can not keep pace with the energy demand, anaerobic respiration supplies the energy continuesly by the breakdown of glucose to lactic acid.
(1) The planet of earth in its early time had an environment which was totally devoid of oxygen. The aerobic organisms can not exist in anaerobic environment.
(2) Some existing organisms, like bacteria and parasites which live in oxygen environment, have anaerobic respiration and many useful bacteria and yeast are anaerobic.
(3) Even in the aerobic respiration, the first phase is anaerobic. The glycolysis which is the first phase of carbohydrate metabolism involves reaction which do not require the expedition of molecular oxygen. This may in a way support the notion that aerobic organisms have evolved from the anaerobic organisms.
(4) In some active tissues like skeletal muscles, although aerobic metabolism takes place but in sustained activity when the oxygen supply can not keep pace with the energy demand, anaerobic respiration supplies the energy continuesly by the breakdown of glucose to lactic acid.