Membrane Potential Laboratory

The interactive model presented below simultaneously plots membrane potentials as predicted by the
  • Nernst Equilibrium Relationship for K+, and the
  • Goldman, Hodgin, Katz (GHK) equation.
The Nernst relationship for K+ is
and is depicted by the "blue" curve where
  • [K+]o varies from 0.1 to 140.0 mM along the X axis and
  • [K+]i is set by the investigator.
The GHK relationship is
It is depicted by the "black" curve where
  • [K+]o varies from 0.1 to 140.0 mM and
  • [K+]i and alpha are set by the investigator.

Experiment with altering [K+]i and/or alpha to see how changes in these values alter the membrane potential for any given value of [K+]o .