1.4

Question 1

ion channels are:

Answer 1

1. pore forming, transmemb. proteins
2. passive
3. selective
4. gated
5. fast

Question 2

what are the general functions of ion channels?

Answer 2

1. establish resting memb. potential
2. shaping AP
3. regulate cell volume

Question 3

in what ways can we classify ion channels?

Answer 3

• based on ion charge
• based on gating mechanism
• ion type

Question 4

give examples for different ion channels based on gating mechanism?

Answer 4

1. voltagae gated
2. second messenger gated
3. ligand gated
4. mechanosensitive
5. heat/light sensitive

Question 5

what are the 3 configurations of voltage gated Na+ channel?

Answer 5

1, closed but activatable

2. open
3. close but inactivatable

Question 6

what are Inwardly-Rectifing K+ channels?

Answer 6

passes + current more easily into the cell than out of it

Question 7

where can we find Inwardly-Rectifing K+ channels?

Answer 7

cardiac myocytes to slow membrane repolarization

Question 8

which subunit in the VG Ca++ Channel forms the pore?

Answer 8

a1

Question 9

functions of VG Ca++ Channel

Answer 9

• Ca++ sensitive K+ channel activation
• muscular contraction
• Hormone/NT release
• Gene expression regulation

Question 10

L-Type VG Ca++ Channel location

Answer 10

skeletal m
smooth m
ventricular myocytes

Question 11

L-Type VG Ca++ Channel functions

Answer 11

cardiac AP plateau

smooth+skeletal m contraction

Question 12

T-Type VG Ca++ Channel location

Answer 12

SA node

Question 13

T-Type VG Ca++ Channel functions

Answer 13

pace maker activity

Question 14

N-Type VG Ca++ Channel location

Answer 14

brain and PNS

Question 15

N-Type VG Ca++ Channel functions

Answer 15

synaptic NT vesicle release