Resting membrane potentials (wk 9)

Question 1

The electrochemical gradient is a combo of what two gradients

Answer 1

concentration gradient

electrical gradient

Question 2

at ____ there is no net movement of ions

Answer 2

equilibrium

Question 3

The direction that K+ flows down its concentration gradient @ rest

Answer 3

flows out of the cell

Question 4

The direction that NA+ and Cl- flow down their concentration gradient at rest

Answer 4

into the cell

Question 5

Is there a higher intra or extracellular concentration of K+

Answer 5

intracellular

so it will flow out

Question 6

Is there a higher intra/ extracellular concentration of Na+ and CL-

Answer 6

extracellular concentration

so they will flow into the cell

Question 7

Na+/ K+ / ATPase is ______

Answer 7

electrogenic –> they change the e- potential of the membrane

Question 8

For every ____ + charge brought into the cell, there are ___+ charges pushed out

Answer 8

2+ charges in
3+ charges out

(keeps the inside neg. charged)

Question 9

___ & ___ carry negative charges

Answer 9

Proteins and ATP

Question 10

Proteins and ATP are confined to the _______ environment

Answer 10

intracellular environment

• they are negatively charged, so it keeps a neg. charge in the cell

Question 11

Cell membrane is ____ permeable

Answer 11

seelectively permeable

Question 12

At rest, the cell is mostly only permeable to ___

Answer 12

K+

Question 13

def______: net separation of charge across the membrane

Answer 13

membrane potential

potential NRG from the chemical concentration gradient

Question 14

Membrane potential is usually around _____mV

Answer 14

-70 mV

Question 15

def: ____: membrane potential when there is a balance btw electrical and chemical forces

Answer 15

equilibrium potential

Question 16

What 2 factors is an equilibrium potential based on

Answer 16

1. intra/ extracellular concentration

2. electrical charge of the ion

Question 17

Equilibrium potential predicts (2)

Answer 17

1. direction of ionic flow

2. driving force nd resting membrane potential

Question 18

????def: ______: the membrane potential at which there is no net (overall) flow of that particular ion from one side of the membrane to the other.

Answer 18

Nernst potential

aka: reversal potential

Question 19

K+ flows in the direction of ___ charge

Answer 19

negative charge

Where ever there is more negative charge (in or out of the cell) K+ will move in that direction to neurtralize it

Question 20

Figure out SLIDE 10 & 11

Answer 20

blah =(

Question 21

Most of the cells resting membrane potential is determined by the equilibrium potential for ____

Answer 21

K+

Question 22

At rest, most open ion channels are ____

Answer 22

leaky K+ channels

Question 23

resting membrane potential values for most cells range from ___ to ___

Answer 23

-65mV to -95 mV

Question 24

2 factors that affect the resting membrane potential

Answer 24

1. concentration gradient of Na+ , K+, and Cl-

2. cell’s permeability to each

Question 25

GHK equation determines the resting potential when there is :______

Answer 25

NO NET DIFFUSION of all ions across the cell membrane

Question 26

Nernst equation determines the resting potential when there is : ______

Answer 26

No NET DIFFUSION of any oen given ion

Question 27

Ion channels have ____ & ___ gates that open and close

Answer 27

voltage gates

ligand gates

Question 28

The “driving force” of ionic flow can also be described as ______

Answer 28

electric current

Question 29

The larger the diriving force the ______ the ionic current will travel

Answer 29

faster the ionic current once the cell becomes permeable to that ion