The negative charge established along the cytosolic border a nerve cell membrane is due to
A)movement of sodium ions into the cell
B)movement of proteins out of the cell
C)higher permeability of K+ relative to Na+
D)movement of proteins through membrane channels
E)both b and d

Question

Quizplus · Accepted Answer

The negative charge along the cytosolic border of a nerve cell membrane is due to the higher permeability of K+ relative to Na+. This allows for K+ to flow out of the cell down its concentration gradient, leaving behind negatively charged protein anions in the cytosol, resulting in a negative membrane potential. Movement of sodium ions into the cell would actually result in depolarization and a positive membrane potential. Movement of proteins out of the cell or through membrane channels would not contribute to the establishment of the negative membrane potential. Therefore, answer choices B and D are incorrect. Choice E is also incorrect because only one of the options actually contributes to the negative membrane potential.

The Negative Charge Established Along the Cytosolic Border a Nerve