A nerve cell maintains low intracellular Na+ and high extracellular Na+ even though Na+ tends to leak inward. When metabolic poisons block ATP synthesis, intracellular Na+ rises and the gradient collapses within minutes.
The protein shown most closely resembles which kind of transporter?
- A
A receptor that does not move ions
- B
A passive ion channel that opens at depolarization
- Ccheck_circle
An ATP-driven pump performing active transport against the gradient
- D
A simple aquaporin
Explanation
Active transport pumps (e.g., Na+/K+ ATPase) hydrolyze ATP to move ions against gradients; without ATP, the pump stops and gradients dissipate.