Little biophysics exercise - Nerst eq

[GGM]

Hi evryone,

I'm new in this forum and I didn't see an "exercise/ Q&A" topic, so I decided to post it here.

 

In a cell (negative internal), a positive ion has a equilibrium potential of "-90 mV" , which contrasts a concentration of "135 mM / L" (between the cell's inside and outside).

Indicate if the ion's concentration is greater outside or inside.

 

I suppose that I've to use Nerst eq to find out if ln(out/in) is >1 or 0<x<1. Can you help me?

 

P.S. Sorry for my bad english.

Edited June 26, 2017 by GGM

[hypervalent_iodine]

Where exactly are you stuck?

[GGM]

Now I solve it setting xout+xin=1, so i've just the variable "xin" (xout=1-xin) .

 

z=+1 .

Ex= (61,5/z) * log(1-xin/xin)

 

Is correct?

 

My result is " 0.96% ion is intracellular and 0.04 extracellular".