test 2 lec 2 part 2

Question 1

Hyper-polarization part 1

_ Chloride currents

Answer 1

gets activated very readily at the membrane resting potential. It helps keep the membrane hyperpolarized. o Higher concentration outside o Moves in (influx)- generate downward deflection

Question 2

Hyper-polarization part 1

_ Potassium currents

Answer 2

contributed most to the membrane resting potential o Higher concentration inside o Moves out (efflux) _ outward current

Question 3

Hyper-polarization part 1

what is the class of Chloride channel

Answer 3

ClV1.1

Question 4

Hyper-polarization part 1

Chloride currents and toxins?

Answer 4

_ Chlorotoxins -derived from scorpion _ Flufenamate (synthetic) _ Tamoxifen

Question 5

Hyper-polarization part 1

what is Tamoxifen used for?

Answer 5

primary use is oncology for treatment of breast cancer _ blockage of estrogen receptors), it side effect is Cl channel blocker

Question 6

Hyper-polarization part 1

what are some of the K+ channel toxin sources?

Answer 6

_ Plants and animals

Question 7

Hyper-polarization part 1

why is K+ so important to the cell?

Answer 7

K+ repolarizes the membrane potential so that you don_t stay permanently depolarized. It also regulates the membrane potential; make it more or less hyperpolarized

Question 8

Hyper-polarization part 1

4 major classes of K channels

Answer 8

1. Classic voltage-dependent K channels (VDKC) 2. Rectifier (means to make normal) K+ channels (maintain balance, 3. Metabotropic-gated K+ channels (second messenger cascades)), 4. Ca2+-dependent K+ channels (CDKC)- very sensitive to free intracellular Ca2+

Question 9

Hyper-polarization part 1

what are the Classic voltage-dependent K channels (VDKC)?

Answer 9

_ IA (A for the first type found) _ ID (D stand for delayed) _ IK _ delayed rectifier _ IM _ Muscarinic sensitive K+ Channels.

Question 10

Hyper-polarization part 1

what are the Rectifier (means to make normal) K+ channels?

Answer 10

_ IK _ Anomalous (means different) rectifier _ IH(Q) (hyperpolarization activated) _ Tandem

Question 11

Hyper-polarization part 1

what are the features of Tandom channels?

Answer 11

(implies 2pore) pore _ 2 pores in ion channel; very common; explained how volatile anesthetics work

Question 12

Hyper-polarization part 1

what are the Metabotropic-gated K+ channels (second messenger cascades)?

Answer 12

1-IM (muscarinic sensitive channels, ACh channel) , 2-ATP-sensitive , 3-IAHP (After Hyperpolarization) , 4-IsAHP (slow AHP)

Question 13

Hyper-polarization part 1

what are the 4. Ca2+-dependent K+ channels (CDKC)?

Answer 13

1- IC (C=Calcium) 2- IM 3- IAHP 4- IsAHP