The transporters which can help in both active as well as passive transport of molecules are
Solution:
Carrier proteins facilitate the movement of molecules across the cell membrane. They can be involved in facilitated diffusion (a type of passive transport) where molecules move down their concentration gradient, or in active transport where molecules are moved against their concentration gradient, often requiring energy directly or indirectly. For example, glucose transporters are carrier proteins that facilitate passive transport, while some secondary active transporters are also carrier proteins. Pumps are specifically involved in primary active transport, using ATP directly. Channels (including aquaporins) primarily facilitate passive transport (facilitated diffusion) without direct energy expenditure.