ATPase is which type of pump?

ATPase is which type of pump?
a) Secondary active
b) Electrogenic
c) Symport
d) All of the above
Correct Answer - B
Ans. B. Electrogenic
[Ref Ganong 24th/e p.51, 10; Guyton 12th/e p.53]
Sodium-potassium pump:

  • Most important pump for primary active transport in body.
  • An Electrogenic pump.
  • Responsible for maintaining Na+ & K+ conc. difference across cell
  • ICF - High K+ concentration.
  • ECF - High Na+ concentration.
  • Both Na+ & K+ transported against concentration gradient.
  • Uses energy by hydrolyzing ATP;
  • Pump contains ATPase activity.
  • Na±K+ pump extrudes -
  • 3 Na+ out from cell.
  • Pumps 2 K+ into cell.
  • Coupling ratio of Na±K+pump - 3:2