ADP

A high-energy phosphoric acid compound.

ADP is a core component of energy storage, metabolism, and signal transduction in the body, and is a precursor to ATP, under which it is widely used in cellular processes, including respiration, biosynthetic reactions, motility, and cell division. It is formed by connecting two phosphoryl groups with a pyrophosphate bond, and then connecting with adenosine 51-C through a phosphate bond.