Adenosine Triphosphate

Adenosine triphosphate (ATP) is considered by biologists to be the energy currency of life. It is the high-energy molecule that stores the energy we need to do just about everything we do. It is present in every cell, and essentially all the physiological mechanisms that require energy for operation obtain it directly from the stored ATP. As food in the cells is gradually oxidized, the released energy is used to re-form the ATP so that the cell always maintains a supply of this essential molecule.

Living things can use ATP like a battery. The ATP can power needed reactions by losing one of its phosphorous groups to form ADP (adenosine diphosphate), but food energy can be used in the cell to convert the ADP back to ATP so that the energy is again available to do needed work.