Which of the Following is NOT True of the Equlibrium

Question

Which of the following is NOT true of the equlibrium potential?
A) It is the potential at which the flux of an ion is zero
B) It is the potential at which diffusive force balances electrical force
C) It is the potential for which $\Delta$$\mu$ for an ion is zero
D) It is the potential at which the conductance for an ion is zero
E) It is the potential at which the Nernst equation gives the membrane potential

Accepted Answer

The equilibrium potential is defined by the balance of electrical and diffusive forces (B), leading to no net flux of ions (A), and where the chemical potential difference ($\Delta\mu$) for an ion across the membrane is zero (C). It is also the potential predicted by the Nernst equation for a given ion (E). However, it does not imply that the conductance (the ability of an ion to conduct electrical current across the membrane) for an ion is zero (D). Conductance depends on the presence and activity of ion channels, not on the equilibrium potential itself.