Which of the following is TRUE about the concentration gradient of Na⁺ in a neuron at rest?
A)It favors its movement into the cell at the resting membrane potential.
B)It favors its movement out of the cell at the resting membrane potential.
C)It is equal and opposite to the electrical potential acting on Na⁺ at the resting membrane potential.
D)It is in the same direction as the diffusion potential due to the concentration gradient for K⁺.
E)It favors movement of Na⁺ in the opposite direction as the electrical potential acting on Na⁺ at the resting membrane potential.

Question

Which of the following is TRUE about the concentration gradient of Na⁺ in a neuron at rest?
A)It favors its movement into the cell at the resting membrane potential.
B)It favors its movement out of the cell at the resting membrane potential.
C)It is equal and opposite to the electrical potential acting on Na⁺ at the resting membrane potential.
D)It is in the same direction as the diffusion potential due to the concentration gradient for K⁺.
E)It favors movement of Na⁺ in the opposite direction as the electrical potential acting on Na⁺ at the resting membrane potential.

Quizplus · Accepted Answer

EAt the resting membrane potential, the concentration gradient of Na⁺ favors its movement into the cell because the concentration of Na⁺ is higher outside the cell than inside. Additionally, the electrical potential inside the neuron is negative relative to the outside, which also attracts the positively charged Na⁺ ions into the cell, making statement E true as it indicates that the movement favored by the concentration gradient (into the cell) is in the opposite direction to that favored by the electrical potential (which also attracts Na⁺ into the cell).

Which of the Following Is TRUE About the Concentration Gradient