Which type of protein adds a phosphate group to another molecule?

Kinase Enzyme

Explanation:

Kinase is an enzyme that catalyzes a biochemical reaction where it transfers phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation. During phosphorylation, the substrate gains a phosphate group and the high-energy ATP molecule donates a phosphate group.

Kinases belong to the enzyme family of phosphotransferases. Kinases are different from phosphorylases, as the latter catalyzes the reaction where inorganic phosphate is added to the substrate. Therefore, kinases are essential enzyme in human physiology.