|ADP (ā'dē'pē') Pronunciation Key
Short for adenosine diphosphate. An organic compound that is composed of adenosine and two phosphate groups. With the addition of another phosphate group, it is converted to ATP for the storage of energy during cell metabolism. It then forms again, from ATP, when a phosphate group is removed to release energy. Chemical formula: C10H15N5O10P2.