Final answer:
Enzymes that add phosphate groups to protein targets are called kinases. This process, known as phosphorylation, can activate or deactivate the function of the protein and is catalyzed by kinases. Phosphorylation can be reversed by enzymes known as phosphatases.
Step-by-step explanation:
Enzymes that add phosphate groups to protein targets are called kinases.
Phosphorylation is a common post-translational modification (PTM) where a phosphate group is added to proteins. The transfer of the phosphate group is catalyzed by an enzyme called a kinase. Kinases specifically add phosphate groups to residues of the amino acids serine, threonine, or tyrosine. This phosphorylation can activate or deactivate the function of the protein, and it can be reversed by another enzyme called a phosphatase.