
Answer:
active transport
Explanation:
Active transportĀ is the energy-requiring process of pumpingĀ moleculesĀ andĀ ions across membranesĀ "uphill" against a gradient. TheĀ active transportĀ of smallĀ moleculesĀ orions acrossĀ a cellĀ membraneĀ is generally carried out byĀ transport proteinsĀ that are foundĀ inĀ theĀ membrane.