2) Membrane Potential (20 pnts): Consider a neuron at body temperature with the ionic concentrations below: lon Permeability Intracellular Extracellular Concentration (mm) Concentration (mm) Chloride 0.50 500 Potassium 1.00 500 15 55 Sodium 0.05 50 400 a) Calculate the equilibrium potential (Nernst potential) for each ion. (4 points) b) Using the information in the table above, calculate the membrane potential. (4 points) c) At the membrane potential, which direction would be the net sodium ion flow, from inside of the cell towards outside or vice versa? (4 points) d) If the extracellular sodium ion concentration is reduced to zero, what will be the new membrane potential? (4 points) e) Why do you think that such a change in sodium concentration does not have a strong influence on membrane potential? Can you reason why membrane potential takes a value around the Nernst potentials of chloride and potassium ions? (4 points)