Resting Membrane Potential

Question 1

Potential (E)

Answer 1

a voltage-separation of charge (in this case across the membrane) gives the ability to do work

Question 2

Resting Membrane Potential

Answer 2

The difference between the inside and outside of a cell at rest (as steady state requires continual work and energy to maintain)

Question 3

Depolarization

Answer 3

TOWARDS 0!

A change in the membrane potential

Question 4

Is Resting membrane potential in equilibrium

Answer 4

no-steady state-it requires E

Question 5

-50 –> -10V is?

Answer 5

Depolarization

Question 6

+50 –> +10

Answer 6

Depolarization

Question 7

Hyperpolarization

Answer 7

Away from 0

Question 8

Current and units

Answer 8

Movement of charge (ions) in Amperes (A)

Question 9

Resistance (R) and untis

Answer 9

Opposition to the flow of charge in Ohms

Question 10

Ohm’s law

Answer 10

V=IR (Voltage=Current x Resistance)

Question 11

Permeability

Answer 11

The ease with which a particular ION moves through an open channel

Question 12

Conductance (g)

Answer 12

Opposite of resistance

-Defined as the ease of flow of CURRENT through an ion channel-the inverse of resistance

Question 13

the inverse of resistance is

Answer 13

conductance

Question 14

Na/K ATPase pumps what? Type of transporter

Answer 14

Primary transport-3 Na OUT and 2 K IN (per ATP)

Question 15

Electrogenic

Answer 15

cell becomes more negative

(you lose one net charge by pumping 3+ out and just 2 +in

Question 16

Two roles of the Na/K transported in the resting membrane potential

Answer 16

Indirect-most important-establishes ion gradient

Direct=electrogenic effect net flow of + out and - in

Question 17

Most important role of Na/K pump

Answer 17

indirect-ion [c] –> gradient

Question 18

What happens if you block Na/K pump

Answer 18

cell depolarizes from -70 to -55 or so

Question 19

Indirect effect of Na/K pump

Answer 19

creates a Na and K gradient

Question 20

electroneutrality

Answer 20

Cations and anions in each solution must exactly balance-if you had all one charge everywhere they would repel-thus the charge is associated with the membrane not in bulk solution

Question 21

Generally more Cl- where and why?

Answer 21

Extracellular to balance - charge of organic ions-this might not always be the case

Question 22

Where is the charge that creates membrane potential and why does it matter

Answer 22

Near the membrane-duh

Matters because you could not have lots of one charge floating around solution

Question 23

Do you need to move a lot of ions in order to change the charge?

Answer 23

Nope

Question 24

Electrical potential vs chemical potential

Answer 24

Electrical potential is a diff in charge (of all charge particles)

Chemical potential is a concentration outside vs the concentration on the inside (of a single ion type)

Question 25

Equilibrium (reversal) potential

Answer 25

The membrane potential at which no net flux of an ion occurs-or in other words when an ion is allowed to move freely this is the potential that the ion will equilibrate at! -Called reversal b/c it is when the direction of ion through a channel is reversed

Question 26

Which equation describes equilibrium potential

Answer 26

Nernst Equation

Question 27

Know how to use and calc Nernst

Answer 27

..

Question 28

R, T, F means

Answer 28

R=gas constant T= temp F=Faradays constant

Question 29

Go - beyond equilibrium potential ion does what

Answer 29

moves in

Question 30

Go + from eq. potential

Answer 30

ion moves out

Question 31

Reversal potential for Na is about?

Answer 31

+60mV

Question 32

Increasing Ion permeability does what | use K as ex

Answer 32

Increasing the membrane permeability of a particular ion will drive the membrane potential toward the equilibrium potential of that ion K will drive membrane potential to -90

Question 33

Which ion has the largest effect on resting membrane potential?

Answer 33

K

Question 34

Sodium permeability at rest

Answer 34

LOW

Question 35

If you let Na freely move

Answer 35

Brings membrane potential to +60V (depolarizing)

Question 36

Electrogenic activity of the Na+/K+ ATPase adds how much charge?

Answer 36

~10 mV (direct effect)