The sodium-potassium pump is called an electrogenic pump because it
A) pumps equal quantities of Na⁺ and K⁺ across the membrane.
B) pumps hydrogen ions out of the cell.
C) contributes to the membrane potential.
D) ionizes sodium and potassium atoms.
E) is used to drive the transport of other molecules against a concentration gradient.

Question

Quizplus · Accepted Answer

The sodium-potassium pump contributes to the membrane potential by actively transporting 3 Na⁺ ions out of the cell and 2 K⁺ ions into the cell, creating an electrochemical gradient. This makes it an electrogenic pump.

Answer: A, D, and E are incorrect

A) The pump does not pump equal quantities of Na⁺ and K⁺, but rather pumps out 3 Na⁺ ions for every 2 K⁺ ions it pumps in.
B) The pump does not pump out hydrogen ions.
D) The pump does not ionize sodium and potassium atoms.
E) The pump is not used to drive the transport of other molecules against a concentration gradient, but rather maintains the concentration gradients of Na⁺ and K⁺ by using ATP.

The Sodium-Potassium Pump Is Called an Electrogenic Pump Because It