What is the Primary Difference Between Diffusion and Facilitated Diffusion

Question

What is the primary difference between diffusion and facilitated diffusion?
A) One is active and the other is passive.
B) One requires ATP and the other doesn't.
C) Diffusion involves the movement of a substance from high concentration to a lower concentration. Facilitated diffusion moves a substance from a lower concentration to a higher concentration.
D) Facilitated diffusion uses a "helper" molecule to move a substance passively.

Accepted Answer

The primary difference between diffusion and facilitated diffusion is that facilitated diffusion uses a "helper" molecule to move a substance passively. Diffusion, on the other hand, occurs without the help of a helper molecule and involves the movement of a substance from high concentration to a lower concentration. Choices A and B are incorrect as both diffusion and facilitated diffusion are passive processes that do not require energy input. Choice C is also incorrect as both processes involve movement from a higher concentration to lower concentration.