Question

The potassium equilibrium potential is -94 mV. What does this mean?

a) The concentration of potassium inside the cell is greater than outside the cell.
b) The electrical force on potassium ions is directed into the cell.
c) Potassium ions will move out of the cell due to chemical and electrical forces.
d) The potassium equilibrium potential is not influenced by concentration gradients.

Answer 1

The potassium equilibrium potential of -94 mV means that the electrical force opposing potassium movement into the cell exactly balances the chemical force driving it out, preventing any net movement.

Step-by-step explanation:

The potassium equilibrium potential of -94 mV indicates the electrical and chemical forces acting on potassium ions (K+) across a cell membrane. In essence, this value represents the potential at which potassium ion movement due to the concentration gradient is balanced by the electrical gradient, resulting in no net movement of K+ ions into or out of the cell.

As K+ ions have a higher concentration inside the cell compared to outside, their tendency is to move out, following the concentration gradient. This movement creates a negative charge inside the cell. However, at the equilibrium potential of -94 mV, the electrical force is such that it exactly opposes the chemical driving force due to the concentration gradient, preventing further net movement of K+.