L8 Receptors Flashcards Preview

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Flashcards in L8 Receptors Deck (42)
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1

Function of receptors

detect physical and chemical stimuli

2

Proteins embedded in plasma membrane detect

extracellular ligands

3

Transmembrane receptor function

transfer signal across plasma membrane

4

Intracellular receptors detect

permeable stimuli (gases, liquids)

5

No of receptor families in mammalian genome

25

6

What do members of each family share

one or more structurally homologous domains

7

Ion channels regulate

membrane potential

8

Effectors for ion channels

ions

9

Chemical signal generated by ion channels

change in ion composition of the cell

10

Ion channel key features

pore selectivity, gating mechanism

11

Ion pore selectivity

defined by physical size of filter and amino acids lining pore

12

Gating mechanism

ligand or voltage

13

Function of +ve charges in amino acids

voltage sensitivity

14

p loops location

between two TMs

15

TM receptors

transmembrane receptors

16

p loops function

create highly selective filter

17

Ion channel structure

subunits come together with pore in center

18

Closely packed TMs function

gate that blocks ion passage

19

Voltage gated ion channel gating

gating controlled by voltage sensing domain

20

Voltage gated K channel Kv1 structure

4 subunits each with 6 TMs

21

Inactivation peptide function in Kv1

blocks open pore

22

Kv1 additional units

beta cytoplasmic subunits

23

Ligand gates ion channels gating

gated by intracellularly or extracellularly chemical stimuli

24

Example of pentameric extracellular ligand gated ion channel

5HT, GABA

25

Example of tetrameric extracellular ligand gated ion channel

NMDA

26

Example of trimeric extracellular ligand gated ion channel

P2XR

27

What channels control membrane excitability

Na+/K+ selective channels

28

Cl- selective channels effect on CM

hyperpolarise cells

29

Glutamate ligand gated ion channels structure

dimer of dimers, binding site in cleft

30

Glutamate ligand gated ion channel binding site location

extended N terminal