Question

1. the sodium - potassium pump is a type of active transport that moves sodium and potassium through the membrane. based on what you know about active transport, which statement must be true of a sodium - potassium pump?

a. the sodium - potassium pump moves sodium ions and potassium ions through facilitated diffusion.
b. the sodium - potassium pump requires energy and a protein to move sodium and potassium ions.
c. the sodium - potassium pump moves both sodium and potassium ions into the cell through diffusion.
d. the sodium - potassium pump moves both sodium and potassium ions out of the cell through passive transport.

Explanation:

Active transport requires energy (usually in the form of ATP) and often uses transport proteins. The sodium - potassium pump is a protein that actively transports sodium ions out of the cell and potassium ions into the cell against their concentration gradients. Facilitated diffusion (Option A) is a form of passive transport (no energy required). Diffusion (Option C) is a passive process (no energy) and the sodium - potassium pump does not move both ions into the cell. Passive transport (Option D) does not require energy, and the pump does not move both ions out of the cell.

Answer:

B. The sodium - potassium pump requires energy and a protein to move sodium and potassium ions.