Question 1 (5 points) Consider a typical cell at its resting membrane potential (rest Vm). The membrane temporarily becomes more permeable to Cl-....

Question 1 (5 points)

Consider a typical cell at its resting membrane potential (rest Vm). The membrane temporarily becomes more permeable to Cl-.

Ecl = -65mV, resting Vm = -60mV

Part I: Electrochemical Gradient

Does a chemical force (gradient) exist, if so in what direction? (.5 point)

Does an electrical force (gradient) exist, if so in what direction? (.5 point)

What direction will the ion flow (said another way, what is the electrochemical gradient? (.5 point)

Draw your representation of what is occurring at questions 1 -3 above and explain your reasoning (explain the physiology taking place) for each gradient. (.5 point)

Part II: Membrane Potential and Equilibrium Potential

Would you expect the membrane potential to change and if so, what direction will the change be? (.5 point)

Would you expect the chloride equilibrium potential to change and if so, what direction will the change be? (.5 point)

Would you expect the membrane to depolarize, repolarize, hyperpolarize, or no change? Both explain in words and draw an appropriate graph to represent visually your answer. (.5 points)

Part III:

If a cell were only permeable to one ion, would the Nernst potential for that ion (Ex) and the resting membrane potential be the same or different (if so how are they different)? (.5 points)

Explain your answer (1 points)