Question

$N{a}^{+}-K^{+}$pump is found in membranes of many cells, like nerve cells. It works against electrochemical gradient and involves an integral protein ATPase. For each molecule of ATP used

• A. $3$ ions of $N{a}^{+}$are pumped out and two $K^{+}$are taken in
• B. $3$ ions of $N{a}^{+}$are taken in and $2K^{+}$are pumped out
• C. $2$ ions of $N{a}^{+}$are thrown out and $3K^{+}$are absorbed
• D. $3$ ions of $K^{+}$are absorbed and $3N{a}^{+}$are pumped out

Answer 1

Answer: (A)

The $N{a}^{+}/K^{+}$-ATPase also known as $N{a}^{+}/K^{+}$pump is an anti-porter-like enzyme located in the plasma membrane of all animal cells. $N{a}^{+}/K^{+}-ATPase$ enzyme pumps sodium out of the cells while pumping potassium into the cells.
The process of moving sodium and potassium ions across the cell membrane is an active transport process involving the hydrolysis of ATP to provide the necessary energy. This process is responsible for maintaining the large excess of $N{a}^{+}$outside the cell and the large excess of $K^{+}$ions on the inside. This accomplishes the transport of three $N{a}^{+}$to the outside of the cell and the transport of the two $K^{+}$ions to the inside. This unbalanced charge transfer contributes to the separation of the charge across the membrane. The sodium-potassium pump is an important contributor to the action potential produced by the nerve cells.