When a membrane is at the resting potential, the concentration of
A) sodium and potassium ions is higher on the inside of its membrane than on the outside.
B) sodium and potassium ions is higher on the outside of its membrane than on the inside.
C) sodium ions is higher on the inside of its membrane and of potassium ions is higher on the outside.
D) sodium ions is higher on the outside of its membrane and of potassium ions is higher on the inside.
E) sodium equals the concentration of potassium inside the cell.

Question

Quizplus · Accepted Answer

At rest, the cell membrane is polarized with more negative charges inside the cell and more positive charges outside the cell. This is maintained by the sodium-potassium pump, which actively transports 3 sodium ions out of the cell for every 2 potassium ions transported into the cell. This results in the concentration of sodium ions being higher on the outside of the membrane and the concentration of potassium ions being higher on the inside of the membrane. Choice D describes this situation.

When a Membrane Is at the Resting Potential, the Concentration