The use of proteins in a cell
membrane to move molecule from a
low concentration on one side to a
high concentration on the other.

The use of proteins in a cell  membrane to move molecule from a  low concentration on one side to a  high concentration on the other is done by membrane transport proteins (Carrier proteins)

Explanation:

Carrier- mediated transport can be described as a type of transport in which carrier molecules assist in the movement of molecules inside or outside the cell.

There are two types of membrane transport proteins:

Channel proteins can be described as proteins which open channels in the cell membrane. Molecules tend to move along the concentration gradient i.e from a higher concentration to a lower concentration through this phenomenon.

Carrier proteins can be described as proteins which open in one direction only. The facilitate the movement of molecules against the concentration gradient i.e from a lower concentration to a higher concentration.