Question

which type of transport moves particles without energy through a protein channel?
a) facilitated diffuson
b) active transport
c) osmosis
d) exocytosis

Explanation:

• Option A: Facilitated diffusion is a passive transport (no energy required) where particles move through protein channels (or carriers) down their concentration gradient.
• Option B: Active transport requires energy (ATP) to move particles against the concentration gradient, so it's incorrect.
• Option C: Osmosis is the diffusion of water across a semi - permeable membrane, not through protein channels for general particles, so it's incorrect.
• Option D: Exocytosis is a process where cells release large molecules (like proteins) by fusing vesicles with the membrane, it's an active process and not about moving particles through protein channels in the described way, so it's incorrect.

Answer:

A) Facilitated Diffusion