Question

Chloride has an equilibrium potential of -90 mV. What direction are the chemical and electrical forces acting on the anion at the resting membrane potential (-70 mV)?

A) The chemical force is directed into the cell and the electrical force is directed out of the cell.

B) Both the chemical and electrical forces are directed out of the cell.

C) The chemical force is directed out of the cell and the electrical force is directed into the cell.

D) Both the chemical and electrical forces are directed into the cell.

E) There is insufficient information to answer this question.

Answer 1

At a resting membrane potential of -70 mV, the chemical force on chloride ions is directed into the cell, while the electrical force is directed out of the cell. A) The chemical force is directed into the cell and the electrical force is directed out of the cell.

Step-by-step explanation:

At a resting membrane potential of -70 mV, chloride ions (Cl-) will experience a chemical force that tends to drive them into the cell because the interior is more negative compared to the outside at -70 mV, despite chloride having an equilibrium potential of -90 mV.

Meanwhile, because the inside of the cell is less negative than chloride's equilibrium potential, the electrical force will tend to drive the chloride ions out of the cell. The concentration of Cl- is higher outside of the neuron, establishing a gradient for Cl- to move into the cell to balance the concentrations, representing the chemical force. The electrical force refers to the charge difference, with chloride ions being repelled from the negatively charged area (outside the cell) toward the less negatively charged area (inside the cell).