What term refers to a pore in the cell membrane that allows ions to move by opening and closing?

What term refers to a pore in the cell membrane that allows ions to move by opening and closing?

• A. Facilitated diffusion
• B. Gated ion channel
• C. Sodium-potassium pump
• D. Active transport

Answer: (B)

The idea here is gated control of ion flow through a membrane pore. A gated ion channel is a channel protein that forms a pore allowing specific ions to pass only when it is open. The opening and closing (gating) can be triggered by voltage changes, ligand binding, or mechanical stimuli. When open, ions move by diffusion down their electrochemical gradient—this is a passive process known as facilitated diffusion through a channel. This differs from active transport, like the sodium-potassium pump, which uses energy to move ions against their gradients. So the term that describes a pore that opens and closes to let ions through is gated ion channel.

The idea here is gated control of ion flow through a membrane pore. A gated ion channel is a channel protein that forms a pore allowing specific ions to pass only when it is open. The opening and closing (gating) can be triggered by voltage changes, ligand binding, or mechanical stimuli. When open, ions move by diffusion down their electrochemical gradient—this is a passive process known as facilitated diffusion through a channel. This differs from active transport, like the sodium-potassium pump, which uses energy to move ions against their gradients. So the term that describes a pore that opens and closes to let ions through is gated ion channel.