Question

Plot the voltage of the cell using the original parameters for Na, K and Cl, and...

Plot the voltage of the cell using the original parameters for Na, K and Cl, and changing sodium permeability from 1 to 10, 100, 1000 and up to 9999. Will the voltage keep increasing positively as the permeability to sodium is increasing? Why?












Plot the voltage of the cell using the original parameters for Na, K and Cl, and changing potassium permeability from 1 to 10, 100, 1000 and up to 9999. Will the voltage keep increasing negatively as the permeability to potassium is increasing? Why?














In the Goldman equation, Ki and Nai are on the top of the equation ratio, but Cli is on the bottom. Why?










Summary:
State the important principles that you have discovered in working with the Goldman equation using the Nernst/Goldman simulator.












Homework Answers

Answer #1

1ans.increase the permeability of an axonal membrane to sodium ions, the equilibrium potential for sodium in the cell .increase, because the influx of sodium depolarizes the neuron.balance the inward directed chemical gradient for Na+, the cell interior needs to be +52 mV to prevent Na+ from diffusing into the cell. ... Therefore, while the resting potential is far removed from the ENa, the peak of the action potential approaches ENa.

2ans.increase the membrane potential (hyperpolarize the cell) because the presence of extra potassium outside the cell will make the potassium equilibrium potential more negative. c. increase the membrane potential because the excess positive charge on the outside of the cell makes the inside relatively more negative.

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