ATPase

An ATPase is an enzyme that catalyzes the decomposition of ATP into ADP plus an inorganic phosphate ion. This dephosphorylation is widely used in all known forms of life as a mechanism for driving energetically unfavourable reactions; as such, ATPases are rarely dedicated solely to dephosphorylating ATP, but rather couple this reaction to some other reaction and use the ATP dephosphorylation as a source of energy.