MathBench > Cellular Processes

Nernst Potential

 

Taking Nernst for a test drive

 

nernst eqation

 

typical cellThe Nernst equation on the right is related to the Goldman equation but it allows you to calculate the membrane potential for individual ions.  Let’s give it a try for the potassium ion and the sodium ion.  The figure on the right gives you the information you need for the Nernst equation.

 

 

What is the Nernst potential associated with the potassium ion?

(To make this problem interactive, turn on javascript!)

I think I have the answer: -90 mV

Bet you thought that was going to be harder... Let's try another one

What is the Nernst potential associated with the sodium ion?

(To make this problem interactive, turn on javascript!)

I think I have the answer: +72 mV