BIOL 219
Spring 2013
Outline for “Membrane Potential” lecture
Definition of membrane potential
3 factors that determine membrane potential
Concentrations of ions across the plasma membrane
Relative permeability of the membrane to specific ions
Activity of the Na+-K+ ATPase pump
Resting Membrane Potential
Origins
K+ example – Nernst equation
Na+ example – Nernst equation
Membrane permeability
K+ has more effect on RMP than Na+
Importance of Na+-K+ ATPase
Objectives: After today’s lecture you should . . .
(1) Know the 3 factors that determine membrane potential.
(2) Define membrane potential.
(3) Know what resting membrane potential is and how it is determined.
(4) Identify the ions most important in determining membrane potential.
(5) Be able to explain how concentration and electrical gradients affect ion
movement.
(6) Know the significance of ion equilibrium potentials.
(7) Know how to calculate an ion equilibrium potential using the Nernst
equation.
(8) How do you know if the concentration or electrical gradient is stronger?