Control of Blood Glucose concentration Flashcards
(15 cards)
What are factors that affect blood glucose concentration?
Food intake as glucose is absorbed into blood during digestion, exercise as the demand for glucose increases, and metabolic rate as the demand for glucose increases.
What are the 3 key processes involved in the control of blood glucose concentration?
Glycogenesis which is he conversion of glucose into glycogen. Glycogenolysis which is the hydrolysis of glycogen into glucose. Gluconeogenesis which is the conversion of non-carbohydrates into glucose.
What is the role of the pancreas in the control of blood glucose concentration?
Alpha cells detect low blood glucose and secrete glucagon. Beta cells detect high blood glucose and secrete insulin.
What is the role of insulin in controlling high blood glucose concentration?
If blood glucose becomes too high, insulin binds to specific receptors on CSM of target cells.
What are the 3 main effects of insulin?
1) Causes glucose channel proteins to change shape and open so more glucose can enter the cell.
2) Triggers fusion of channel-containing vesicles with CSM of target cell, increasing the number of glucose channel proteins in the membrane so more glucose can enter the cell.
3) Activation of enzymes involved in formation of glycogen from glucose (glycogenesis).
It also increases the rate of respiration.
What is the role of glucagon in controlling low blood glucose concentration?
If blood glucose concentration is too low, glucagon binds to specific receptors on CSM of target cells.
What are the 2 main effects of glucagon?
1) Activation of enzymes that convert glycogen into glucose (glycogenolysis).
2) Activation o enzymes that convert glycerol and amino acids into glucose (glyconeogenesis).
What is the role of adrenaline in controlling low blood glucose concentration?
Adrenaline binds to specific receptors on CSM or target cells which activates enzymes that convert glycogen into glucose (glycogenolysis).
Describe the process of the second messenger model.
1) Glucagon/adrenaline binds to receptor on CSM of target cell (liver cell).
2) This activates an adenylate cyclase enzyme.
3) Adenylate cyclase catalyses production of cAMP from ATP.
4) cAMP activates protein kinase enzyme. Protein kinase activates a chain of reactions (cascade effect) that leads to glycogenolysis.
What are the causes of type 1 diabetes?
Pancreas don’t produce enough insulin due to an autoimmune disease that destroys insulin-producing beta cells.
What are the symptoms of type 1 diabetes?
Being thirsty due to an increase in blood glucose as the water potential of blood decreases. Excessive urination due to higher fluid intake. And weight loss due to respiration of lipids.
What is the treatment of type 1 diabetes?
Regular insulin injections and careful management of diet and exercise.
What are the causes of type 2 diabetes?
Pancreas may not produce enough insulin or the glycoprotein receptors on CSM of target cells become less responsive to insulin.
What are the symptoms of type 2 diabetes?
Associated with obesity.
What is the treatment of type 2 diabetes?
Careful management of diet and exercise, and losing weight.
