Ion pumps enable ions to flow through membranes in a
thermodynamically uphill direction by the use of an energy source
such as ATP or light. They consist of sugar-containing hetero-peptide
assemblies, which open and close upon the binding and subsequent
hydrolysis of ATP, usually transporting more than one ion towards
the outside or the inside of the
membrane.
Source:
PAC, 1997, 69, 1251
(Glossary of terms used in bioinorganic chemistry (IUPAC Recommendations 1997))
on page 1281