Hormones & the regulation of blood glucose concentration Flashcards Preview

Biology: topic 16 > Hormones & the regulation of blood glucose concentration > Flashcards

Flashcards in Hormones & the regulation of blood glucose concentration Deck (9):

What are hormones?

-chemical messengers
-secreted form glands into the blood
-carried by the blood plasma to target cells
-widespread, long lasting effects


What is the second messenger model?

-hormones activate chemical pathways in calls by binding to receptors on the cells to create a second messenger chemical to be produced in cells by activating an enzyme in the cell by changing its tertiary structure
-for example adrenaline causes ATP to produce cAMP which activates an enzyme which converts glycogen to glucose


What is the role of the pancreas in regulating blood glucose?

-it produces enzymes for digestion and the hormones insulin and glycogen from the islets of Langerhans


What are the cells of the islets of Langerhans?

-alpha cells = larger, produce glucagon when there is a low concentration of glucose as glucagon converts glucose to glycogen and forms glucose from glycogen
-beta cells = smaller, produce insulin when the blood glucose level is high as it opens chemical pathways for glucose to be stored as glycogen and fat, it also increases the respiratory rate


Which sources do blood glucose come from?

- hydrolysis of food


What is blood glucose?

-normally 90mg
-eating increases blood glucose
-exercise decreases blood glucose


What does adrenaline do?

-produces glucose for the fight or flight response
-produces by adrenal glands above the kidneys
-breaks down glycogen
-synthesises glycogen


What is the feedback mechanism?

-glucagon increases glucose levels
-insulin decreases glucose levels which prevents it ever getting too high or too low


What are the three important processes associated with regulating blood sugar which take place in the liver?

-glycogenesis: the conversion of glucose into glycogen when glucose concentration is high
-glycogenolysis: breakdown of glycogen to glucose when glucose concentration is low
-gluconeogenesis: glucose is produced from glycerol and amino acids when there is no glycogen