Quiz 4

Question 1

Nernst Equation

Answer 1

Ex=RT/zF ln([x]out/[X]in)

Question 2

Common Nernst Potentials

Answer 2

Ek= -93
Ena= +61
Ecl= -75

Question 3

Nernst Potential

Answer 3

membrane potential that a single ion would produce if the membrane was permeable to only that ion

Question 4

Synonyms for Nernst Potential

Answer 4

equilibrium potential
reversal potential

Question 5

equilibrium potential

Answer 5

membrane potential at which a given ion net flux is 0

Question 6

reversal potential

Answer 6

membrane potential at which a given ions flux reverses from inward to outward

Question 7

if Ex=Vm

Answer 7

no net flow

Question 8

if Ex>Vm

Answer 8

reverses flow

Question 9

if Ex<Vm

Answer 9

flows with gradient

Question 10

equilibrium potentials set boundaries

Answer 10

ceiling- Ena
floor- Ek

Question 11

Negative Vm inside moves ____ ions ___

Answer 11

positive
in

Question 12

depolarization

Answer 12

changing membrane potential to be more positive

Question 13

repolarization

Answer 13

returning membrane potential towards resting potential

Question 14

hyperpolarization

Answer 14

changing membrane potential to be more negative

Question 15

GHK Equation

Answer 15

V= RT/F ln Pk[k]out+Pna[na]out+Pcl[cl]in/ Pk[k]in+Pna[na]in+Pcl[Cl]out
weighted average of Ex for each ion

Question 16

What does GHK predict?

Answer 16

the potential that results from the contribution of all membrane-permeable ions

Question 17

At rest Vm is close to ___

Answer 17

Ek, because the membrane is mostly permeable to K

Question 18

Ions with ____ permeability have ____ influence on V

Answer 18

greater
greater

Question 19

The membrane is in ____ not equilibrium.

Answer 19

steady state

Question 20

steady state

Answer 20

unchanging state that remains so only by constant input/output

Question 21

At rest Vm=?

Answer 21

-70

Question 22

Can change the membrane potential by…

Answer 22

changing the permeability of different ions