Homeostasis blood glucose control Flashcards
Why does blood glucose concentration need to be so carefully controlled?
All cells need a constant energy supply to work
What is the normal concentration of blood glucose?
Around 90 mg per 100 cm³ of blood
What is blood glucose concentration monitor by?
The pancreas
What two hormones control, blood glucose concentration
Insulin and glucagon
What cells secrete, insulin and glucagon?
Islets of Langerhans
What cells to secrete insulin into the blood?
Beta cells
What cells secrete glucagon into the blood?
Alpha cells
Describe the action of insulin low in blood glucose concentration
1)Insulin binds to specific receptors in the cell 2)membranes of liver cells in muscle cells
It increases the permeability of cell membranes to glucose, so the cells take up more glucose
3) Insulin also activates enzymes that convert glucose to glycogen
4) Cells are able to store glycogen in the cytoplasm as an energy source
5) The process of forming glycogen is called glycogenesis
6) Insulin also increases the rate of respiration of glucose, especially in muscle cells
What’s the process of forming glycogen from glucose called?
Glycogenesis
Describe the action of glucagon, raising blood glucose concentration
1) Glucagon binds to specific receptors on the cell membranes of liver cells
2) Glucagon activates enzymes that break down glycogen into glucose
3) The process of breaking down glycogen is called glycogenolysis
4) Glucagon also promotes a formation of glucose from glycerol and amino acids
5) The process of forming glucose from non-carbohydrate is called Gluconeogenesis
6) Glucagon decreases the rate of respiration of glucose in cells
The process of breaking down glycogen
Glycogenolysis
The process of forming glucose from non-carbohydrates
Gluconeogenesis
When do beta cells secrete insulin?
When they detect high blood glucose concentration
