Lecture 9: Metabolism in the Fed and Starved States

Question 1

which hormones activate glycogenolysis / gluconeogenesis and which inactivate it

Answer 1

activate:
- glucagon
- cortisol
- adrenaline
inactivate:
- insulin

Question 2

what effect does citrate have on PFK-1

Answer 2

inhibits it

Question 3

what happens in the glucose fatty acid cycle

Answer 3

• fatty acid oxidation
• converted to acetyl CoA
• converted to citrate
• inhibits PFK-1
• build up of G-6-P
• inhibits hexokinase
• build up of glucose
• prevents further glucose entry

Question 4

what do glucagon and adrenaline phosphorylate and what effect does this have

Answer 4

• phosphorylase kinase, which phosphorylates phosphorylase, turning it on
• glycogen synthase, turning it off

Question 5

what does insulin activate and what effect does this have

Answer 5

• phosphotase-1
• dephosphorylates phosphorylase kinase and phosphorylase, turning them off
• dephosphorylates glycogen synthase, turning it on