Receptors

Question 1

Ligand gated (ionotropic) - function

Answer 1

Binding site - pore opens - ions through

Question 2

Ionotropic - speed

Answer 2

Fast

Question 3

Ionotropic - structure

Answer 3

• 4 or 5 protein subunits
• each subunit has a string of amino acids which span the cell membrane 4 times
• ‘rosette’ / doughnut shaped

Question 4

Ionotropic - ions

Answer 4

• Inhibitory neurotransmitter action leads to entry of Cl-
• Excitatory - entry of Ca2+

Question 5

Ionotropic - receptors

Answer 5

GABA-A
NMDA
5HT3

Question 6

Metabotropic (G protein coupled receptors) - function

Answer 6

Ions bind - activate G protein - influences opening of ion channels, affects enzymes and second messengers

Question 7

Metabotropic - speed

Answer 7

Slow, more widespread effects

Question 8

Metabotropic - structure

Answer 8

Span cell membrane 7 times

Gs - stimulatory
Gi - inhibit adenylate cyclase
Third subtype act via phospholipase C

Question 9

Metabotropic - receptors

Answer 9

DA
Most 5HT
NEN
Opioid receptors

Question 10

Nuclear receptors

Answer 10

Glucocorticoid receptors, receptors for progesterone, androgen, vit D

Cysteine-rich DNA-binding domain - becomes transcription factor - binds to DNA via zinc fingers