Question

Resting membrane potential is -65 mV. ENa = +58 mV, EK = -75 mV, and ECl = -70 mV. Opening of which ion channel(s) should hyperpolarize the membrane?

A.Na+
B.K+
C.Na+ and K+
D.K+ and Cl-
E. Na+ and Cl

Answer 1

Opening K+ and Cl- channels would hyperpolarize the cell membrane, as their equilibrium potentials are more negative than the resting membrane potential. K+ outflow or Cl- influx will make the interior of the cell more negative.

Step-by-step explanation:

The opening of certain ion channels can influence the membrane potential of a neuron. If the resting membrane potential is -65 mV, and the equilibrium potentials for Na+, K+, and Cl- are +58 mV, -75 mV, and -70 mV respectively, opening ion channels that move the membrane potential towards their equilibrium will change the polarization state of the cell. In accordance, the channels that would hyperpolarize the membrane when opened are those for K+ and Cl-, as their equilibrium potentials are more negative than the resting membrane potential. Opening of K+ channels allows K+ to move out of the cell, making the inside of the cell more negative. Likewise, opening of Cl- channels would also hyperpolarize the membrane as Cl- would move into the cell, increasing the negative charge inside.