Lecture 3 Flashcards Preview

106: Receptors and Cellular signalling > Lecture 3 > Flashcards

Flashcards in Lecture 3 Deck (18):
1

When is glucagon released and from where?

released when blood glucose is low
- from alpha cells in the islets of Langerhans in the pancreas

2

Where is glucagon released to?

liver cells glucagon receptors

3

What does glucagon inactivate; what happens; via protein kinase A?

phosphofructokinase 2
- suppresses glycolysis

4

what does glucagon activate; what happens; via protein kinase A

fructose bisphosphatase 2
- stimulates gluconeogenesis

5

What does Protein kinase A do?

phosphorylate proteins eg. such as those in glucagon and epinephrine schemes to activate them

6

What does epinephrine do?

raises blood glucose levels
- dialates blood vessels

7

what does glucagon do?

maintains homeostasis

8

where is epinephrine released from?

adrenal glands
to the muscle cells and adipose tissues

9

What does epinephrine activate via protein kinase A

phosphorylase kinase

10

What does epinephrine inactivate via protein kinase A

glycogen synthase

11

What is the overall effect of epinephrine in the body

glucose degredation

12

why are there so many steps in these signalling systems?

to enable tight control of hormonal actions

13

what are the common components of the two hormone mediated events

- both involve a stimulatory G protein
- both involve increase in the secondary messenger cAMP
- both involve activation of protein kinase A

14

different components of these two hormone mediated events?

protein kinase A phosphorylates different targets

15

What drug is commonly used to trigger cAMP production today?

Byetta

16

what does Byetta do?

-mimics GLT-1
- peptide drug (must be injected)
- increases insulin secretions

17

why does epinephrine get triggered during flight or fight response

ensure energy availability

18

when does glucagon get triggered?

during low levels of blood glucose; to ensure energy availability