A

David

Darling

phosphorylation

Phosphorylation is a biochemical reaction in which a phosphate group is introduced into a molecule. Controlled by the enzyme phosphorylase, it is the initial state in many natural biochemical processes, such as the conversion adenosine diphosphate (ADP) to energy-rich adenosine triphosphate (ATP). Phosphorylation is also an important reaction in the activation or deactivation of enzymes, often under hormone control.