resting membrane potential - (Nov/08/2008 )

Hi there,

just wondering about the following...it the notes it says:

If Vm is less negative than Ek, potassium ions flow out of the cell (+ve current by convention), while if Vm is more negative than Ek, then ions flow inward (negative current)..

so just wondering when potassium ions flow out of the cell this makes the cell more negative right thus ultimately reaching the equilibrium potential for potassium of about -97mV..and if ions are flowing inwards this is making the cell more postive..if so are the potassium ions moving against their concentration gradient to enter the cell?

Thanks, hopefully someone can reply soon as needa know by thursday (still time but would like to know asap),

Cheers,
b_06er

Active transport?

Hi,

sorry wasn't looking for an anwer for the above post just if I had the concept right of what the notes were trying to explain...so basically when ions flow into a cell is this regarded as -ve by convention and +ve if ions are leaving the cell?...Does this convention apply to all ions?

but here's another question:
which terms in the below equation model potassium conductance? I have highlighted what I think, am I right? or does it not include 'n'?
Im=m^3hg(Na)(Vm-ENa) + n^4g(K)(Vm-EK)

Thanks,
b_06er

The equation bit looks right, the other half appears to apply to sodium (Na)

I suspect the current conventions will be the reverse if you are modelling negatively charged ions, but I haven't done this sort of stuff for about 10 years.