<prompt> Which of them is TRUE about Na-K pump:K is pumped against the gradient.2K are exchanged with 5NaHypercalcemia causes arrest in Na K pump.Increase in intracellular Na increases action potential.  <response>: Ans. is a i.e. K is pumped against the gradient Na-K pump or Na-K ATPase, extrude 3 Na from the cell and take 2 K into the cell. Thus its coupling ratio is 3:2.It pumps both Na K against their concentration gradients by utilizing energy from the hydrolysis of ATRBecause of this differences in the charges moved in and out, it is an electrogenic pump. Increase in intracellular Na, decrease the height of action potential. 