Membrane potentials part 1

channel

how do some ions need to get thru

high to low

what direction do concentration go

opposites=

attract

magnitude

how strong the push is (weak force=small difference, strong push=big diff)

direction

opposite attract, same aparts

ATP

what do cells need to push one place to another

3 Na+ out and 2 K+ in, unbalanced

how much Na+ and K+ are pushed out/in

membrane potential

charge, difference of inside and out

0mV

what is the mV for the outside of the cell

resting membrane potential (RMP)

steady cell (-70mV)

typical cell for Na+

outside: 150mm, inside: 15mm

typical cell for Cl-

outside: 150mm, inside, 10mm

typical cell for K+

outside: 5mm, inside:150mm

mV gets higher (closer to 9)

what happens when ions go thru channel

C=

high to low

E=

electric force (opposite=goes in, same=goes out)

net

which arrow is stronger

depolarization

move closer to 0mV

hyperpolarization

moves father from 0mV

no electric gradiant

what happen when in and out of cell both 0mV

equilibrium

no net force (C&E same)

vM given in question

use nernst equation

if vM=Ex=equalibrium

equilibrium potential (Ex)

when the membrane potential is equal (C&E cancel out)

nernst equation

Eion=RT/ZF X log (ion ECF/ion ICF)

61mV

what is always on top of Z in nernst equation