week 2 lecture 3 resting membrane potential

ionic environment inside a typical neuron

higher concentration of K+, low concentrations of Na+ and Cl-

resting membrane potential components

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)

action potential

rapid, temporary reversal of electric polarization across a neuron or muscle cell membrane, functioning as an electrical impulse for communication

Does the sodium-potassium pump set the resting membrane potential of a neuron

Yes

for a neuron at rest what must be true

membrane voltage at -65 mV, ion channels are closed, Na/K pump is moving ions, membrane is alittle leaky

equilibrium potential

specific electrical voltage across a cell membrane of a particular ion

membrane potential

electrical voltage difference across a cell's plasma membrane

permeability

capacity of a membrane to allow specific ions, molecules, or substances to pass through

0

resting

1

threshold

2

depolarization

3

repolarization

4

hyperpolarization

resting membrane potential

the electrical potential difference across the plasma membrane when the cell is in a non-excited state

cell membrane properties

closed ion channel, lipids, opened ion channel, ions, protein subunits of ion channel, pore of ion channel,