The oxidation of carbohydrates and fats in an organism creates several chemical reactions that release enough energy to turn one molecule of ADP into approximately 150 molecules of ATP by adding phosphate groups to the molecule. ATP is adenosine triphosphate and is the energy-bearing molecule found in living cells.
ADP is adenosine diphosphate, used in metabolism and important for moving energy through living cells. ADP is reformed when foods are broken down by the body. The energy in ATP is released or used as a source of power for the cells. ADP is formed when the ATP is decomposed by an interaction with water, referred to as hydrolysis. In order to restore the ATP molecule from the ADP molecule, oxidation must occur, creating a cycle of energy balance.