What would happen to the resting membrane potential 70 mV if

What would happen to the resting membrane potential (-70 mV) if an ion channel opens up whose equilibrium potential is -100mV?

Solution

The resting membrane potential (-70mV) is closer to the potassium potential because of leaky potassium channels i.e. the membrane is more permeable to K ions than the Na ions. If an ion channel open up whose potential is -100mV then the resting membrane potential will decrease even further -70mV. This is because the membrane potential is dependent on the concentration gradients of different ions and the membrane permeability of each ion. We speak majorly of sodium and potassium since they are present in abundance inside/outside a cell. An ion with the potential of -100mV will make the resting membrane potential more negative towards -100mV. A bigger threshold would be required to initiate an action potential.