3.6.4.2 Control of blood glucose (Unit 6 Homeostasis) Flashcards
Define glucoNEOgenesis
Formation of new glucose from amino acids and glycerol.
Define glycogenolysis
Hydrolysis of glycogen into glucose
Define glycogenesis
Formation of glycogen from glucose.
What is lysis?
Splitting
What is genesis?
Creating
Why does blood glucose rise and then fall after a meal?
Why does blood glucose increase in the presence of glucagon ?
Outline the 2nd messenger model of adrenaline action
Where are the hormones that regulate blood glucose secreted?
Islets of langerhan
What do B cells secrete? And when?
Insulin
When blood glucose has INcreased
What do a Cells secrete? And when?
Glucagon
When glucose is a gone
How does insulin lower blood glucose?
Hormone that travels through the blood:
To respiring cells like muscle cells,
and binds to insulin receptors on them.
Causing glucose channels to open
Glucose diffuses in and is used in cellular respiration.
And:
To hepatocytes/receptors on the liver, which insulin binds to and which triggers enzymes involved in glycogenesis.
How does adrenaline increase blood glucose?
Hormone that travels through the blood:
To respiring cells like muscle cells,
and binds to glucagon receptors on them.
Triggering the 2nd messenger model of enzyme action.
Adenylate cyclase catalyses the conversion of ATP->cAMP
cAMP is the 2nd messenger that activates protien Kinase to begin glycogenolysis and gluconeogenesis
And:
To hepatocytes/receptors on the liver, which insulin binds to and which triggers enzymes involved in glycogenolysis and gluconeogenesis.
Describe the effects of insulin
Binds to specific receptors in the liver and muscles
Increases permeability of membranes to glucose – carrier proteins are activated
Activates enzymes to turn glucose into glycogen in glycogenesis (in liver for storage)
Increases the rate of respiration in muscles
Increases the conversion of glucose into fat
Describe the effects of glucagon
Binds to specific receptors in the liver and muscles
Activates enzymes to turn glycogen into glucose (especially in the liver) in glycogenolysis
Promotes making glucose form fatty acids and amino acids in gluconeogenesis
Decreases the rate of respiration in muscles