[Campbell Biology P.181] Which statement accurately distinguishes between channel proteins a... | Practice Question
Which statement accurately distinguishes between channel proteins and carrier proteins?
A: Channel proteins form a hydrophilic tunnel for molecules, while carrier proteins bind to substances and change shape to shuttle them across.
B: Channel proteins transport substances against their concentration gradient, while carrier proteins always facilitate diffusion.
C: Carrier proteins are only specific for ions, whereas channel proteins transport a wide variety of molecules.
D: Channel proteins require energy investment for transport, while carrier proteins never do.
Explanation
The text describes channel proteins as functioning by having a hydrophilic channel that molecules or ions use as a tunnel, while carrier proteins hold on to their passengers and change shape to shuttle them across the membrane. This outlines their distinct mechanisms of action.