In this essay we will discuss about the oxygen cycle with the help of a diagram.
Oxygen is about 20-84% in the atmosphere. Organisms respire aerobically in the presence of oxygen.During respiration, it combines with hydrogen to form water. It is found as a component of oxidised salts CO2 arid H2O.
Oxygen enters the plants and animals through respiration during which carbohydrate or any other respiratory fuel is oxidized to form CO2 and water. It is also used in combustion of wood, coal, petroleum etc. to yield CO2, SO2, water, oxides of nitrogen, etc. Microbial oxidation produces variety of oxides. The oxygen in the atmosphere is in a state of dynamic equilibrium. Organisms get it from air or water for oxidative reactions (respiration).
Oxygen is mainly produced during the photolysis of water in the light phase of photosynthesis. It is again made available to environment in combination with carbon in the form of CO2 or with hydrogen as H2O. Oxygen is also released as a part of CO2 due to death and decay of organic matter (Fig. 14.27).