Question

7. If a cell were placed in a solution with a high potassium concentration and no sodium, what would happen to the sodium-potassium pump's activity?

A. It would stop moving ions across the membrane.
B. It would continue using ATP to pump sodium out of the cell and potassium into the cell.
C. It would move sodium and potassium ions across the membrane, but no ATP would be used.
D. It would reverse the direction of sodium and potassium ions to move against their gradients.

Answer 1

The sodium-potassium pump requires ATP for its function, and in a high potassium environment, its activity would continue but may be less efficient. Without ATP, the pump would cease to operate.

Step-by-step explanation:

The sodium-potassium pump is a vital component in maintaining the electrochemical gradient across the cell membrane. If a cell were placed in a solution with a high potassium concentration and no sodium, the activity of the sodium-potassium pump would likely continue, yet it may function less efficiently due to the altered ion gradients. However, without ATP, as described in the second part of the question, the sodium-potassium pump would not function, and it would not use any ATP to pump ions across the membrane because ATP is crucial for the energy transfer necessary to move ions against their concentration gradients. Therefore, the correct answer to the first part is B. It would continue using ATP to pump sodium out of the cell and potassium into the cell, although with reduced efficiency, and for the second part, if no ATP were present, the sodium-potassium pump would not be able to operate and move ions across the membrane.