electric potential

Question 1

normal in/out [C] of Na and K

Answer 1

K: 140in and 4 out
Na: 14in and 142out

Question 2

what does Na/K pump do

Answer 2

2 K in for 3 Na out at cost of 1 ATP

Question 3

normal inner cell e

Answer 3

-70mV

Question 4

define equilibrium potential

Answer 4

E(x) = the amount of electrical potential that counters diffusion

Question 5

what is equilibrium potential for Na and K

Answer 5

Na: +61
K: -94

Question 6

why does resting potential end up at -70

Answer 6

membrane more permeable to K

Question 7

key to determining resting potential

Answer 7

resting potential will be closer to ion with most permiability

Question 8

what is structure of protein channel

Answer 8

protein in membrane with a water channel running through it

Question 9

what are 2 main states of protein channel

Answer 9

1. conducting

2. non-conducing

Question 10

what is transition period between called

Answer 10

gating

Question 11

what are 3 things that can gate a channel

Answer 11

1. action potential
2. ligand - receptor binding
3. stretch or stress

Question 12

what is K permeability of membrane at rest

Answer 12

very permeable

Question 13

4 key features of action potentials

Answer 13

1. all-or-nothing
2. constant amplitude
3. initiated by depolarization
4. constant velocity

Question 14

4 stages of action potential

Answer 14

1. upstroke
2. downstroke
3. hyperpolarization
4. resting

Question 15

what happens to ion channels in upstroke

Answer 15

Na opens

Question 16

what happens to ion channel in downstroke

Answer 16

Na closes, K opens

Question 17

what happens to ion channel in hyperpolarization

Answer 17

K open means almost hit E(K)

Question 18

3 stages of potential transmission

Answer 18

1. rest
2. initiation
3. propagation