What is a consequence of ATP deficiency for the Na/K pump's function?

What is a consequence of ATP deficiency for the Na/K pump's function?

• A. It becomes more efficient at pumping ions.
• B. It stops functioning entirely, causing immediate cell death.
• C. It reverses ion gradients.
• D. It cannot maintain normal electrical membrane status, disrupting impulse propagation.

Answer: (D)

Maintaining the resting membrane potential depends on the Na+/K+ ATPase, which uses ATP to move three Na+ out and two K+ in. When ATP is scarce, the pump slows or stops, allowing Na+ to accumulate inside and K+ to leak out, so the inside of the cell becomes less negative. This depolarization disrupts the normal electrical status of the membrane, making it harder for neurons and muscle cells to fire action potentials and propagate impulses. The pump doesn’t instantly vanish or reverse ion gradients; instead, its reduced activity gradually degrades the gradients, leading to impaired excitability and signal conduction.

Maintaining the resting membrane potential depends on the Na+/K+ ATPase, which uses ATP to move three Na+ out and two K+ in. When ATP is scarce, the pump slows or stops, allowing Na+ to accumulate inside and K+ to leak out, so the inside of the cell becomes less negative. This depolarization disrupts the normal electrical status of the membrane, making it harder for neurons and muscle cells to fire action potentials and propagate impulses. The pump doesn’t instantly vanish or reverse ion gradients; instead, its reduced activity gradually degrades the gradients, leading to impaired excitability and signal conduction.