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Flashcards in Ion Channels Deck (54)
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1

metabotropic receptors

Receptors that activate second messenger pathways which can affect physically separate ion channels

1

Each pentameric ligand gated channel subunit has four transmembrane alpha helices (M1 through M4), with ____ assembling around the central pathway.

M2

1

The ion is stabilized within the pore by energetic interactions with the _____.

amino acids forming the pore

2

ionotropic receptors

receptors that are directly coupled to ion channels

2

Ions must be substantially dehydrated before they pass through the _____.

channel pore

3

The pentameric ligand gated channels are either selective for ____, or allow permeation of both sodium and potassium.

chloride

3

Voltage sensing is accomplished by the ____.

S4 helices

4

The reversal of inactivation is called ________.

“removal of inactivation."

6

Voltage gated channels of the______ have four membrane-spanning domains, each of which contains six alpha helices (S1 through S6).

KV, NaV and CaV families

7

Neurotransmitter receptors are either _____ or ______.

directly coupled to ion channels; activate second messenger pathways

8

For both K(V) and Na(V), gating is controlled by ____.

membrane potential (Vm)

9

______ are structural tetramers.

Aquaporin water channels

10

After the _____ opens, the inactivation gate closes.

activation gate

11

Voltage gated channels of the KV, NaV and CaV families have _____, each of which contains six alpha helices (S1 through S6).

four membrane-spanning domains

12

Pentameric ligand gated channels include ____, ____, _____, and _____.

GABAARs, GlyRs, nAChRs, 5-HT3Rs

13

What do channels select for?

1) size 2) charge 3) dehydration 4) multiple binding sites

14

activation

opening the gate to allow K+ to flow out of the cell

15

After the activation gate opens, the inactivation gate closes, a process called ______.

inactivation

16

Aquaporin water channels are structural ______.

tetramers

17

When the _____ is made positive, the gate rotates to its _____ and K+ ions flow out of the cell.

inside; open position

17

deactivation

closing of the gate to decay the current

17

_______ is accomplished by the S4 helices.

Voltage sensing

18

When the____ is made negative the gate rotates back to the closed position and _____.

inside of the cell; the current decays away

20

Receptors that activate second messenger pathways which can affect physically separate ion channels are called ________.

metabotropic receptors

21

When the inside of the cell is made _____ the gate rotates back to the _____ position and the current decays away.

negative; closed

22

After the activation gate opens, the ______ closes.

inactivation gate

23

The pentameric ligand gated channels are either selective for the permeation of chloride, or allow permeation of both _____ and _____.

sodium and potassium

24

The pentameric ligand gated channels are structurally ______.

heteropentamers

25

_______ have two of its four subunits bind glutamate and the other two bind glycine.

NMDA receptors

26

Ions are ______ in solution by waters of hydration.

energetically stabilized