Antiport

Some proteins function as co-transport systems in which the transfer of one dissolved substance depends on the simultaneous or sequential transfer of another substance, either in the same direction or in the opposite direction.

Antiport - the transfer of another substance in the opposite direction . For example, the sodium-potassium pump in eukaryotic plasma membranes works according to the antiport principle, pumping sodium ions from the cell, and potassium ions into the cell.