Unit 2.1 - Membrane Potential

Resting Membrane Potential

Plasma membranes are usually electrically polarized.

The voltage difference across the membrane is a form of transmembrane voltage.

Start of membrane potential is a function of ionic concentration gradients and permeabilities.

Equilibrium Potential

Loss of K⁺ intracellularly creates an electrical gradient.

Negative ions will try to pull K⁺ back into the intracellular space.

When concentration and electrical gradient are equal, membrane is at its equilibrium potential.

Depolarization

Membrane potential becomes less negative than the resting membrane potential.

Repolarization

Membrane potential returns to the resting membrane potential.

Hyperpolarization

Membrane potential becomes more negative than the resting membrane potential.