WHAT  IS   RESPIRATION

Respiration  may be briefly defined  as the exchange of  environmental oxygen with the carbon dioxide produced in the cells during oxidation at a most surface. This process generally involves (i) intake of molecular oxygen from the environment,(ii) step- wise oxidation of food with the incoming oxygen,(iii) elimination of carbon dioxide produced in oxidation,(iv) release of energy in
small dose during oxidation,and (v) conservation of energy so released in biologically usefull forms,such as ATP .