Biological processes involve both catabolism, the breaking down of high-energy molecules into simple molecules, and anabolism, the building of complex molecules from simple ones. in general, catabolic processes generate energy, whereas anabolic processes require energy. the energy is usually stored in intermediate energy-carrying molecules such as adenosine triphosphate (atp).

ATP is the energy currency of the cell. ATP is used in the metabolic process of the body and used for the transportation of molecules. The ATP hydrolysis gives ADP and inorganic phosphate.

The highest energy form of the ATP is adenosine. The adenosine molecules contains three phosphate group. The ATP molecules acts as a fuel for the endergonic reactions of the body. ATP molecules can diffuse in the area where as active process occurs and they drive chemical energy by the breaking of phosphodiester bond.