Action Potentials III Answer 2

• Stepping the membrane potential to a value more negative than the equilibrium potential for potassium would mean that the electrical gradient would oppose and would be greater than the balance of the concentration and electrical gradients for potassium (i.e., the potassium Nernst potential), and would become a net inward current.
• A net inward current is depolarizing, so the response of the potassium ion flux would be to move the membrane back to the equilibrium potential for potassium ions, i.e., depolarize it back to -75 mV.