Hormones and regulation of blood glucose Flashcards
Where are hormones produced?
Glands
How are hormones transported?
Via bloodstream
What is the process for the second messenger model?
Adrenaline binds to protein receptor on liver cell surface membrane
Binding of adrenaline causes protein shape change inside cell
Change in protein shape activates enzyme adenyl cyclase.
Activated adenyl cyclase converts ATP to cyclic AMP
cAMP binds to protein kinase and changes its shape to activate it
Activated protein kinase catalyses conversion of glycogen to glucose which diffuses out of liver cell into blood
What are the hormone producing cells in the liver called?
Islets of Langerhans
What are the names of the 2 types of cell found in the islets of Langerhans?
a cells
b cells
Purpose of a cells?
Produce glucagon
Purpose of b cells?
Produce insulin
Which cell found in the islets of Langerhans is bigger?
a cells
What does glycogenisis mean?
Conversion of glucose into glycogen
What does glycogenolysis mean?
Breakdown of glycogen into glucose
What does gluconeogenesis mean?
Production of glucose from other sources than carbs
WHat are the dangers of a low blood glucose conc?
Cells become deprived of energy
Brain cells sensitive as they only respire glucose
What are the dangers of high blood glucose conc?
Lowers blood water potential and can cause dehydration
What are the 3 sources of glucose?
Directly from diet
Glycogenolysis
Gluconeogenesis
What 3 things happen to cells when insulin binds with their glycoprotein receptors?
Shape change of glucose channels, allowing more glucose to enter cells by facilitated diffusion
Increase in number of glucose carrier proteins by stimulating vesicles to fuse with membrane
Activation of enzymes to convert glucose into glycogen and fats
In what 4 ways is blood glucose lowered?
Increase rate of glucose absorption
Increase respiratory rate of cells
Increase glycogenisis
Increase conversion of glucose to fats
What are the effects of glucagon?
Activates enzymes that convert glycogen to glucose
Activates enzymes that convert amino acids and glycerol to glucose (Gluconeogenesis)
Does adrenaline increase or decrease glucose conc?
Increase
