The electrical gradient for K⁺ A) favors its movement out of the cell at resting potential. B) favors its movement into the cell at resting potential. C) opposes the concentration gradient for K⁺ at the equilibrium potential for K⁺. D) both (a) and (c) above. E) both (b) and (c) above.

Question

Quizplus · Accepted Answer

The electrical gradient (or membrane potential) of a cell favors the movement of positively charged ions into the cell and negatively charged ions out of the cell. K⁺ is not a specific ion, but assuming it is a positively charged ion, the electrical gradient would favor its movement into the cell at resting potential. However, at the equilibrium potential (when the electrical gradient is equal and opposite to the concentration gradient), the electrical gradient would oppose the concentration gradient for the ion. Therefore, answer choice E (both b and c) is the best choice.

The Electrical Gradient for K+

The Electrical Gradient for K⁺