Answer:
Kinase is a collective name for a group of enzymes that can apply a phosphate group to another protein or molecule (phosphorylation), while a phosphatase can remove such a group (dephosphorylation). A kinase uses kinetic energy in this catalytic reaction, hence the name kinase.
Often, such a phosphorylation or dephosphorylation activates or deactivates the target protein. This switching function can thus control chemical reactions in the cell and is an important factor in cell-internal signal transduction.
