Question

$N{a}^{+},K^{+}$ pump is found in membranes of many cells, like nerve cells. It work against electro chemical gradient and involve an integral protein ATP. For each molecule of ATP used

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

Answer 1

The correct option is A 3 ions of $N{a}^{+}$ pumped out and 2 $K^{+}$ are taken in.

The sodium-potassium pump is involved in the movement of the sodium and potassium ions across the cell membrane. In this process, ATP is hydrolyzed to liberate energy required for the transport. Hence the process is active that takes place with the help of $N{a}^{+}$/$K^{+}$-ATPase enzyme. In this, three sodium ions are expelled outside the cell and two potassium ions are moved into the cell. Thus the correct answer is option A.