What are the differences between kinase and phosphatase?

Kinase and phosphatase are two types of enzymes that catalyze the transfer of phosphate groups between their substrates. There are a few significant differences between the two. 

Kinase

Kinase is a type of phosphotransferase. It catalyzes the phosphorylation of proteins by transferring a phosphate group from ATP to its protein substrate. 

Kinase adds phosphate groups to proteins. It uses ATP to obtain phosphate groups. The addition of these phosphate groups activates proteins.

Examples of kinases include CDKs, hexokinases, phosphatidylinositol kinases, and MAPKs. 

Phosphatase

Phosphatase is a type of hydrolase. It catalyzes the dephosphorylation of proteins by transferring a phosphate group from a phosphoprotein to a water molecule. 

Phosphatase removes phosphate groups from proteins. It uses water molecules to remove phosphate groups. The removal of these phosphate groups deactivates proteins. Proteins that are activated by a kinase can be deactivated by a phosphatase.

Examples of phosphatases include nucleotidases, PP2A, and PP2B.