Blood Glucose Flashcards
What happens if the blood glucose is too high
The water potential of blood is too low
Water diffuse out of cells by osmosis
Cells shrivel and die
What happens if blood glucose it too low
Cells can’t carry out respiration for energy
What causes blood glucose to rise
Eating carbohydrates
What causes blood glucose to decrease
Exercise
What cells secrete insulin and glucagon
Islet of langerhans
Where are islets of langerhans
Pancreas
What cells secrete insulin
Beta cells
What cells secrete glucagon
Alpha cells
How does insulin lower blood glucose
- Insulin binds to specific receptors on muscle and liver cells
- Increases permeability of muscle cell membranes to glucose by increasing number of channel proteins
- Muscle cells take up more glucose
- Activated enzymes that convert glucose to glycogen (glycogenesis)
- Increase rate of respiration
What is glycogenesis
Forming glycogen from glucose
How does glucagon raise blood glucose
- Binds to specific receptors on liver cell membrane
- Activates enzymes that break down glycogen to glucose (glycogenolysis)
- Actives enzymes used to form glucose from glycerol and amino acids
(Gluconeogensis) - Decrease rate of respiration
What is glycogenolysis
Break down of glycogen to glucose
What is gluconeogensis
Forming kudos from non-carbohydrates
Why is a hormone response slower than nervous
Travel in blood to target cells
Why does a hormonal response Last longer than a Nervous response
Hormones aren’t broken down as quickly as neurotransmitters
What is GLUT4
Gousse transported in muscles
Where is GLUT4 in low insulin
Stored in vesicles in cytoplasm
What happens to GLUT4 when insulin binds to receptors
GLUT4 moves to membrane
So glucose can be moved into the cell by fd
Where is Adrenalin released from
Adrenal glands
When is Adrenalin released
Low blood glucose
Exercise
Stress
Where does Adrenalin bind to
Cell membrane of liver cells
What does Adrenalin do
Activated glycogenolysis Inhibits glycogenesis Activates glucagon secretion Inhibits insulin secretion = makes body ready for action by releasing more glucose
How do glucagon and Adrenalin use a secondary messenger to activate glycogenolysis
- Adrenalin and glucagon bind to their specific receptors
- Activates adenylyl cyclase
- Converts ATP to cyclic AMP
- Activates protein kinase A
- Activates a chain of reaction leading to glycogenolysis
What is the secondary messenger with glucose and Adrenalin
Cyclic AMP
Why is the receptor specific to glucagon and adrenalin
Receptor has a specific tertiary structure
