GPCR

Question 1

What is a G protein?

Answer 1

Any protein that binds a G nucleotide

Question 2

How does GPCR work?

Answer 2

• ligand binds to receptor
• when receptor is activates it binds to the G protein
• G protein becomes activates and releases GDP
• allows binding of GTP
• alpha unit disassociates and binds to membrane bound enzymes

Question 3

What does IP3 stand for?

Answer 3

Inositol triphosphate

Question 4

What are If channels?

Answer 4

Hyperpolarizarion cyclic nucleotide activated channels (HCN)

Question 5

How does adrenaline/noradrenaline increase heart rate?

Answer 5

Binds to HCN and increases rate of opening

Question 6

What does cAMP bind to most of the time?

Answer 6

Protein kinase A

Question 7

How does adrenaline breakdown glycogen?

Answer 7

• cAMP activates PKA
• PKA phosphorylates and activates phosphorylase kinase
• phosphorylase kinase phosphorylates glycogen phosphorylase which is what breaks down glycogen

Question 8

How is glycogenesis inhibited?

Answer 8

• PKA inactivates phosphoprotein phosphatase 1

- phosphoprotein phosphatase inactivates glycogen synthase