The enzymes that control activities of other proteins by phosphorylating them are called kinases.

Specifically, they are protein kinases.

Here's why:

* Kinase: This term refers to an enzyme that catalyzes the transfer of a phosphate group from a donor molecule (like ATP) to an acceptor molecule (in this case, a protein).

* Protein: This clarifies that the acceptor molecule is a protein, indicating that the enzyme specifically works on proteins.

So, protein kinases are responsible for adding phosphate groups to proteins, which can alter the protein's shape and activity. This is a crucial mechanism in cellular signaling and regulation.