[Campbell Biology P.184] According to the text, what is a key difference between channel pro... | Practice Question
According to the text, what is a key difference between channel proteins and carrier proteins in facilitated diffusion?
A: Channel proteins require ATP for transport, while carrier proteins do not.
B: Channel proteins directly bind to solutes and change shape, whereas carrier proteins form fixed corridors.
C: Carrier proteins undergo a shape change to translocate solutes, while channel proteins provide a fixed corridor.
D: Only channel proteins facilitate the diffusion of water (aquaporins), while carrier proteins only transport ions.
Explanation
The text states that channel proteins 'simply provide corridors' that allow molecules to cross, while carrier proteins 'seem to undergo a subtle change in shape that somehow translocates the solute-binding site.' This highlights the key difference.