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The weighting of the nernst rises equally for both

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Unformatted text preview: 500 mM VCl= __- 61mv________ Ca++ outside = 5 mM VCa= __- 122 mv Ca++inside = 0.05 mM (a) Write the equilibrium potential at 37 C for each ion in the blanks above (8 pts) (b) We can use a very simple form of the Goldman equation that computes the resting membrane potential as the sum of the equilibrium voltages adjusted for their permeabilities (PK and PCl). Assume that the resting membrane potential is determined only by the potassium and chloride concentrations. Eresting = PK VK PV + Cl Cl PK + PCl PK + PCl If the permeability to potassium and chloride are both 1.0, what is the resting potential for this cell (3 pts)? € Eresting= _____- 61 mV________ (c) If the permeability to both ions is doubled, the membrane resting potential will (put an x in the correct blank below) (3 pts) ____increase by a factor of two remain the same ____decrease by a factor of two Explain your choice above in one sentence. The weighting of the Nernst rises equally for both and, with equal permeabilities will always be the average of both Nernst potentials. (d) If the resting membrane potential was - 100 mV and a channel that allows chloride to pass in either direction suddenly opened, which way will chloride move? Explain your answer below (one sentence). (4 pts) Outward (up the concentration gradient) because the electrical potential would drive the negative outward. This would happen until the concentration gradient yields a Nernst potential that equals - 100 mV 3 Name (print)___________________________________ TA’s name________________ Last First 3. In t...
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This note was uploaded on 02/11/2013 for the course BIO 220 taught by Professor Unsure during the Winter '04 term at University of Washington.

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