At rest,neurons exhibit a negative membrane potential.Among the factors that maintain this polarity,assess which is most DIRECTLY responsible for the difference between intracellular and extracellular ion concentrations? A)movements of negatively charged proteins and nucleic acids across the membrane. B)passive leakage of Na⁺ions across the membrane. C)passive leakage of K⁺ions across the membrane. D)movement of Na⁺ ions through voltage-gated Na⁺ channels. E)movement of K⁺ ions through voltage-gated K⁺ channels.

Question

Quizplus · Accepted Answer

The difference in intracellular and extracellular ion concentrations is primarily due to passive leakage of ions across the membrane. Among the ions that contribute to this difference, potassium (K+) ions have the greatest influence. This is because the cell membrane is more permeable to K+ ions than other ions such as sodium (Na+) and chloride (Cl-) due to the presence of potassium channels, which allow K+ ions to move down their concentration gradient. Therefore, passive leakage of K+ ions across the membrane is the most directly responsible factor for maintaining the negative membrane potential at rest.

At Rest,neurons Exhibit a Negative Membrane Potential