Facilitated diffusion differs from simple diffusion because
A) facilitated diffusion requires energy, simple diffusion does not
B) simple diffusion requires a membrane, but facilitated diffusion does not
C) facilitated diffusion requires a carrier molecule, but simple diffusion does not
D) facilitated diffusion moves substances against a concentration gradient, but simple diffusion moves substances down a concentration gradient
E) in facilitated diffusion, the solvent moves through a membrane, but in simple diffusion the solute moves through the membrane

Question

Quizplus · Accepted Answer

Facilitated diffusion requires a carrier molecule to transport molecules across a membrane, while simple diffusion does not require any carrier molecule. Option A is incorrect because facilitated diffusion does not require energy, but simple diffusion does not require any energy. Option B is incorrect because both facilitated diffusion and simple diffusion require a membrane. Option D is incorrect because facilitated diffusion moves substances down a concentration gradient, while active transport moves substances against a concentration gradient. Option E is incorrect because both facilitated diffusion and simple diffusion involve the movement of solutes through a membrane, not the movement of a solvent.

Facilitated Diffusion Differs from Simple Diffusion Because