Question

The sodium-potassium pump moves ____ Na⁺ and _____ K⁻ simultaneously

a. 2, 3
b. 3, 2
c. 3, 3
d. 2, 2

Answer 1

The sodium-potassium pump moves 3 Na+ ions out and 2 K+ ions into the cell, against their concentration gradients, using ATP.

Step-by-step explanation:

The sodium-potassium pump moves 3 Na+ out of the cell and 2 K+ into the cell simultaneously. Hence, the correct answer is: 3 Na+ and 2 K+. Every single cycle of the sodium-potassium pump uses energy from ATP to maintain the electrochemical gradient across the cell membrane. It does this by expelling three positively charged sodium ions (Na+) from the intracellular space to the extracellular fluid, while importing two positively charged potassium ions (K+) into the cell.

This movement is against their respective concentration gradients, and it is essential for various cellular functions, including nerve impulse transmission and muscle contraction. The pump actively transports three sodium ions out of the cell for every two potassium ions it pumps into the cell. This movement occurs against their respective concentration gradients, requiring energy from ATP.