week 2 lecture 3 resting membrane potential

ionic environment inside a typical neuron

ionic environment outside a typical neuron

resting membrane potential

Na± and K± are key players, ionic driving force, nernst equation

A

closed ion channel

B

lipid molecules in membrane

C

open ion channel

D

ions

E

protein subunits of ion channel

F

pore of ion channel

passive transport

sodium channels (Na+), potassium channels (K+)

active transport

sodium-potassium pump

sodium-potassium pump

required ATP and moves 3 Na+ and 2 K+

ionic driving force

diffusion: concentration gradient, electrical gradient

concentration gradient

which way the ions want to move

electrical gradient

which way the charge pulls the ion

nernst equation

equilibrium potential for a given ion: E_x=-RT/zF ln([X⁺]_i/[X⁺]_o) or E_x=-RT/zF ln([X^-]_o/[X^-]_i)