Question

The function of “sodium pump” is a biological process operating in each and every cell of all animals. Which of the following biologically important ions is also a constituent ion of this pump?
A.${{\text{K}}^{\text{ + }}}$
B.${\text{F}}{{\text{e}}^{{\text{2 + }}}}$
C.${\text{C}}{{\text{a}}^{{\text{2 + }}}}$
D.${\text{M}}{{\text{g}}^{{\text{2 + }}}}$

Answer 1

Hint: The other biologically important ion is a major cation of intracellular fluid of animal cells.It is also an alkali metal ion and it is transferred from the extracellular fluids to the intracellular fluids during the functioning of the sodium pump.

Complete step by step answer:
-Sodium cation is a major cation of extracellular fluids of animals including human beings and is known to activate certain enzymes in the animal body. Sodium ions are relatively harmless except when present in excess amounts. If present in excess, they may cause hypertension.
-The potassium ion is essential to almost all organisms. It is moderately toxic to mammals but only when injected intravenously.
-The sodium and potassium ions taken together constitute the sodium – potassium pump or simply the sodium pump. The functioning of this pump is actually a biological process which takes place in each and every cell of all animals.
-The sodium pump transfers the sodium ions from the intracellular fluids to the extracellular fluids with the help of certain proteins called ‘carrier proteins’. At the same time, the sodium pump also transfers potassium ions into the intracellular fluids from the extracellular fluids.
-Each operation of the sodium pump or in other words, each cycle of this biological process pumps out a huge number of sodium ions from the cell than the number of potassium ions that it pumps into the cell. So, the interior of the cell acquires an excess negative charge and the exterior acquires an excess positive charge.
-As a result, electrical potential gradient is developed across the cell membrane. This is responsible for the nerve signal transmission in animals.

So the correct option is A.

Note:
-The sodium pump also maintains the volume of the cell as without its existence, the cell would have swelled and ultimately bursted.
-If the sodium-potassium pump is blocked, then sodium ion concentration will accumulate within the cell and the intracellular potassium ion concentration will fail. Thus excess of sodium ions inside the cell will lead to toxicity in the animals.