Carrier-mediated transport of a substance down its concentration gradient is called
A)facilitated diffusion.
B)active transport.
C)exocytosis.
D)endocytosis.
E)phagocytosis.

Question

Quizplus · Accepted Answer

Facilitated diffusion involves the use of protein carriers to move substances down their concentration gradient. It is distinct from active transport which moves substances against their concentration gradient and requires energy input. Exocytosis, endocytosis, and phagocytosis involve the movement of large amounts of material across a membrane and are not directly related to carrier-mediated transport down a concentration gradient.

Carrier-Mediated Transport of a Substance Down Its Concentration Gradient Is