L8 Receptors

Question 1

Function of receptors

Answer 1

detect physical and chemical stimuli

Question 2

Proteins embedded in plasma membrane detect

Answer 2

extracellular ligands

Question 3

Transmembrane receptor function

Answer 3

transfer signal across plasma membrane

Question 4

Intracellular receptors detect

Answer 4

permeable stimuli (gases, liquids)

Question 5

No of receptor families in mammalian genome

Answer 5

25

Question 6

What do members of each family share

Answer 6

one or more structurally homologous domains

Question 7

Ion channels regulate

Answer 7

membrane potential

Question 8

Effectors for ion channels

Answer 8

ions

Question 9

Chemical signal generated by ion channels

Answer 9

change in ion composition of the cell

Question 10

Ion channel key features

Answer 10

pore selectivity, gating mechanism

Question 11

Ion pore selectivity

Answer 11

defined by physical size of filter and amino acids lining pore

Question 12

Gating mechanism

Answer 12

ligand or voltage

Question 13

Function of +ve charges in amino acids

Answer 13

voltage sensitivity

Question 14

p loops location

Answer 14

between two TMs

Question 15

TM receptors

Answer 15

transmembrane receptors

Question 16

p loops function

Answer 16

create highly selective filter

Question 17

Ion channel structure

Answer 17

subunits come together with pore in center

Question 18

Closely packed TMs function

Answer 18

gate that blocks ion passage

Question 19

Voltage gated ion channel gating

Answer 19

gating controlled by voltage sensing domain

Question 20

Voltage gated K channel Kv1 structure

Answer 20

4 subunits each with 6 TMs

Question 21

Inactivation peptide function in Kv1

Answer 21

blocks open pore

Question 22

Kv1 additional units

Answer 22

beta cytoplasmic subunits

Question 23

Ligand gates ion channels gating

Answer 23

gated by intracellularly or extracellularly chemical stimuli

Question 24

Example of pentameric extracellular ligand gated ion channel

Answer 24

5HT, GABA

Question 25

Example of tetrameric extracellular ligand gated ion channel

Answer 25

NMDA

Question 26

Example of trimeric extracellular ligand gated ion channel

Answer 26

P2XR

Question 27

What channels control membrane excitability

Answer 27

Na+/K+ selective channels

Question 28

Cl- selective channels effect on CM

Answer 28

hyperpolarise cells

Question 29

Glutamate ligand gated ion channels structure

Answer 29

dimer of dimers, binding site in cleft

Question 30

Glutamate ligand gated ion channel binding site location

Answer 30

extended N terminal

Question 31

Model of binding for glutamate ligand gated ion channels

Answer 31

clamp shell model - conformational change opens pore

Question 32

What contributes to diversity of glutamate receptors

Answer 32

multiple genes, alternative splicing and RNA editing

Question 33

Excess stimulation of NMDA receptors causes

Answer 33

stroke - leads to neuron death

Question 34

Main example of pentameric ligand gated ion channel

Answer 34

nicotinic receptor

Question 35

Pentameric ligand gated ion channel permeability

Answer 35

Na+ and K+

Question 36

Nicotinic receptor structure

Answer 36

5 subunits each with 4 TMs

Question 37

Pentameric ligand gated ion channels binding site

Answer 37

in alpha subunit

Question 38

Advantage of complexity of subunits in one ligand gated ion channel family

Answer 38

diversity, oppurtunity for drug targeting

Question 39

Control of excitability and function of muscle and neurons

Answer 39

by voltage gated ion channels and ligand gated ion channels

Question 40

Myasthenia gravis cause

Answer 40

autoimmune induced loss of muscle nAChR

Question 41

What mutations cause epilepsy

Answer 41

gain of function ion channel mutations

Question 42

What does glutamate receptor signalling regulate

Answer 42

LTP required for memory formation