Intracellular signalling 2

Question 1

Tyrosine kinase receptors are
a. electrogenic
b. catalytic
c. metabotropic
d. G-protein coupled
e. ionotropic

Answer 1

b

Question 2

Match the G-protein-linked receptor to its intracellular signalling pathway
a. vasopressin
b. thrombin
c. β-adrenergic
d. muscarinic
e. glucagon

i. Gs – stimulates production of cAMP
ii. Gi – inhibits production of cAMP
iii. activates phospholipase C

Answer 2

a. iii.
b. iii.
c. i.
d. iii.
e. ii.

Question 3

G-proteins are all
a. heterotrimeric
b. linked to G-protein-coupled receptors
c. monomeric
d. active when bound to GTP
e. 7-pass membrane proteins

Answer 3

d

NOT A becuase - G-proteins can exist in both heterotrimeric and monomeric forms. Heterotrimeric G-proteins consist of three subunits (α, β, and γ), while monomeric G-proteins consist of only one subunit.

Question 4

The part of the tyrosine kinase receptor which insulin binds to is
a. the extracellular tyrosine kinase domain
b. the α subunit
c. the intracellular tyrosine kinase domain
d. the β subunit
e. the janus kinase domain

Answer 4

b

Question 5

The metabolic effects of insulin are mediated by
a. Akt
b. MAPK
c. Raf
d. Ras
e. cAMP

Answer 5

a

Question 6

cAMP is inactivated by
a. hormone-sensitive lipase
b. Akt
c. phosphodiesterase
d. ATPase
e. adenylate cyclase

Answer 6

c

Question 7

Insulin’s moitogenic pathways are mediated by
a. Akt
b. Protein kinase A
c. Protein kinase C
d. cAMP
e. Ras

Answer 7

e

Question 8

The sequence of the pathway involving Ras is

a. Raf-Ras-MEK kinase-MAPK-transcription factor

b. Ras-Raf-MAPK-MEK kinase-transcription factor

c. transcription factor-Raf-MEK kinase-MAPK-Ras

d. Ras-Raf-MEK kinase-MAPK-transcription factor

e. Raf-Ras-MAPK-MEK kinase-transcription factor

Answer 8

d