Question

With respect to the membrane potential which of the following is NOT true?

A. In resting cells, the membrane potential is negative because sodium ions are less permeable than potassium ions.

B. The resting potential of the nerve cell depends on voltage gated potassium channels

C. While chloride is much more permeable than sodium, it adds relatively little to the negative membrane potential.

D. The concentration of chloride inside/outside the cell is the reciprocal of the potassium concentration of the potassium concentration inside/outside.

Answer 1

Ans : Option C

$\odot$ While chloride is much more permeable than sodium, it adds relatively little to the negative membrane potential.

Reason : In most neurons, K+ ion (positively charged ) are present at higher concentrations inside the cell than outside. In contrast, Na+ and Cl- are usually present at higher concentrations outside the cell. K+ is more permeable than Na+ ans Cl- and therefore move outside the cell. This makes inside of the cell negative and outside positive. When chloride is more permeable than sodium it will increase the negative membrane potential as chlorine is a negatively charged ion and the membrane is hyperpolarized.