insulin, glucagon, adrenaline Flashcards
1
Q
what happens in the pancreas when the blood glucose concentration is too low?
A
- beta cells stop secreting insulin
- alpha cells secrete glucagon
2
Q
How does insulin decrease blood glucose level?
A
- binds to specific receptors on the cell membranes of muscle/liver cells
- increases permeability of muscle cell membranes
- activates enzymes in muscle/ liver cells
- these convert glucose –> glycogen (GLYCOGENESIS)
- also increases rate of respiration of glucose in muscle cells
3
Q
how does glucagon increase blood glucose concentration?
second marker model
A
- glucagon binds to receptors on cell membrane of liver cells
- activates adenylate cyclase
- converts ATP to cAMP (second messenger)
- activates protein kinase A
- glycogen broken down to glucose
4
Q
why does adrenaline need to increase blood glucose?
A
-so there is enough glucose available to muscles for respiration
-( to fight/run away)
5
Q
how does adrenaline increase blood glucose concentration?
(second marker model)
A
- adrenaline binds to receptors on cell membrane of liver cells
- activates adenylate cyclase
- converts ATP to cAMP (second messenger)
- activates protein kinase A
- glycogen broken down to glucose
6
Q
on which cells does adrenaline act?
A
liver cells
7
Q
list 4 ways adrenaline increases blood glucose concentration
A
- activates glycogenolysis
- activates glucagon secretion
- inhibits glycogenesis
- inhibits insulin secretion
8
Q
where is adrenaline secreted from?
A
adrenal glands (just above kidneys)
9
Q
what effectors does glucagon act on?
A
liver cells
10
Q
what are the effectors that insulin acts on?
A
muscle/liver cells
