Question

how does facilitated diffusion differ from simple diffusion?
answer

• facilitated diffusion is an active process utilizing carriers.
• atp is expended during facilitated diffusion.
• carrier proteins are involved.
• molecules move against a concentration gradient.
• i dont know yet

Explanation:

1. Analyze each option:

• Option 1: Facilitated diffusion is passive, not active. Eliminate.
• Option 2: Facilitated diffusion is passive, so no ATP expenditure. Eliminate.
• Option 3: Facilitated diffusion uses carrier proteins (or channel proteins), while simple diffusion doesn't. This is correct.
• Option 4: Both simple and facilitated diffusion move down concentration gradients (passive). Active transport moves against. Eliminate.

Answer:

C. Carrier proteins are involved.