In secondary active counter-transport, how do the solutes move?

Secondary active counter-transport involves the movement of solutes across a cell membrane using the energy created by the movement of another solute. In this process, one solute moves into the cell while another moves out, which establishes a concentration gradient for the substances involved. This mechanism is dependent on the gradient created by primary active transport, which uses ATP to move ions, typically sodium or hydrogen ions, across the membrane.

When one solute moves down its concentration gradient, it provides the energy required to move another solute against its concentration gradient. Therefore, in secondary active counter-transport, solutes move in opposite directions. This allows cells to efficiently maintain homeostasis and control the concentrations of various substances within the cytosol and extracellular environment.