L2a - hormones cell surface receptors

Question 1

what happens to the transciption when a hormone interacts with a reccptor

Answer 1

alters the protein function and gene transcription

Question 2

types of hormone receptors

Answer 2

suface and intracellular

Question 3

groups of cell surface receptors

Answer 3

tyrosine kinases (TKs)
- g protein receptors

Question 4

what are TKs

Answer 4

enzymes transferring P from ATP to tyrosine residue

Question 5

wa=hat does phosphorylation induce

Answer 5

conformational change in a protein

Question 6

can activity of TK intrinsic or recuited

Answer 6

both

Question 7

eg of intrinsic TK axtivity

Answer 7

EGF receptor (EGFR)
insulin

Question 8

how family members of EGFR

Answer 8

4

Question 9

structure of EGFR

Answer 9

• hormone binding site
• 2 cytseine rich regions
• single trans-membrane
• kinase domain

Question 10

what signal transduction processes are EGFR involved in

Answer 10

Ras, PI 3-kinase, JAK-STAT

Question 11

what is kinase modification

Answer 11

phosphate group added to it

Question 12

what is phosphate modification

Answer 12

phosphate group removed it

Question 13

what happens during recruited TK activity

Answer 13

the receptor recruits a signal molecule to start transduction

Question 14

how g protein receptor acts tin order to transfer the signal into the cell

Answer 14

• act via second messenger
• like cyclic AMP, IP3, DAG
• phosphorylation and Ca flux happens

Question 15

structure of G subunits

Answer 15

-heterotrimetric, a, B and Y

Question 16

what happens during G coupled receptor signalling

Answer 16

G protein a assocaited with GDP

• hormone induced conformational change to receptor
• GDP exchanged for GTP
• a subunit released and activates 2nd messenger