A cation that is more abundant as a solute in the cytosol of a neuron than it is in the interstitial fluid outside the neuron is
A) HCO3-.
B) Cl-.
C) Ca2+.
D) Na+.
E) K+.

Question

Quizplus · Accepted Answer

The cation that is more abundant as a solute in the cytosol of a neuron than in the interstitial fluid outside the neuron is K+. This is because the resting membrane potential of a neuron is maintained by the Na+/K+ ATPase pump which pumps out Na+ from the cytosol and pumps in K+. Therefore, K+ ions are more concentrated inside the neuron, making it more abundant as a solute in the cytosol compared to the interstitial fluid outside the neuron.

A Cation That Is More Abundant as a Solute in the Cytosol