Answer:
Active transport
Step-by-step explanation:
Active transport refers to the movement of substances up the concentration gradient, which is from the region of their lower concentration to that of the higher concentration. Active transport requires the input of energy to transport the substances against their concentration gradient. It occurs via some membrane proteins that serve as carrier proteins or pumps.
For example, the sodium-potassium pump is a carrier protein uses the energy released during ATP hydrolysis to export three sodium ions (Na+) and import two potassium ions (K+).