Question

Draw a graph showing what would happen to resting membrane potential over time, if the sodium/potassium pump were not functioning. How would this affect a neuron's ability to produce action potentials? What does this imply about the quantity of ions that normally cross the membrane during the course of an action potential?

Answer 1

The above graph depicts the resting membrane potential over time in case of faulty sodium/potassium pump. Normally a cell should maintain a resting membrane potential of -70mv to trigger an action potential for the nerve to carry impulse. In case of break down of sodium/potassium pump, sodium out rush inside the cell down the concentration gradient and potassium would leave the cell down the concentration gradient raising the resting membrane potential around +40 mv. It disrupts the ability of the cell to trigger an action potential which is necessary for the conducting the nerve impulse to the next section. And hence, the neuron will not be able to trigger an action potential.

During a normal action potential, the resting membrane potential is maintained by sodium/potassium pump by regulating the influx and outflux of sodium and potassium ion for every 3 sodium ion pumps in two potassium ions are fluxed out maintaining the equilibrium needed.