CellSig2 - 15

Question 1

5 ways in which receptor-ligand binding occurs

Answer 1

Ionic attraction, van der Waals forces, hydrogen bonding, hydrophobic interaction, surface topology

Question 2

3 excitatory NTs

Answer 2

ACh, Glu, Serotonin

Question 3

2 inhibitory NTs

Answer 3

GABA, Glycine

Question 4

What are the three states of transmitter gated ion channels?

Answer 4

Unoccupied (closed), occupied (open), occupied (closed)(inactivated)

Question 5

Characterise standard AChR

Answer 5

2 alpha, beta, delta, gamma

Question 6

Where does ACh bind to AChRs?

Answer 6

2x on gamma

Question 7

Five classes of enzyme-linked receptors

Answer 7

Receptor tyrosine kinases, tyrosine-kinase associated receptors, receptor-like tyrosine phosphatases, receptor serine/threonin kinases, receptor guanylyl cyclases

Question 8

Outline a tyrosine-kinase linked receptor pathway

Answer 8

Alpha-interferon binds receptors and JAKs cross phosphorylate each other, then their adjacent receptor tyrosines, activating STATs

Question 9

Outline a receptor threonine/serine kinase pathway

Answer 9

TGFb binds types 1 and 2 TGFb receptors (heterodimer), type 2 > p-type 1 > Smad2 or 3 recruitment > pSmad2 or 3

Question 10

Characterise receptor guanylyl cyclase

Answer 10

1TM with EC ligand binding site

Question 11

What is the function of guanylyl cyclase?

Answer 11

IC domain catalyses cGMP formation

Question 12

Outline the guanylyl cyclase pathway

Answer 12

Ligand binds, cGMP forms, then binds and activates cGMP-dependent protein kinase or ion channels

Question 13

What are the signal molecules for guanylyl cyclase?

Answer 13

Natriuretic peptides

Question 14

Outline cooperativity

Answer 14

Due to interactions between ligans and or binding sites in a receptor complex - negative results in binding of one receptor site decreasing affinity at other sites; positive is vice versa

Question 15

What is the outcome of cooperativity?

Answer 15

Sharpening of response