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):
1

What are hormones?

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

2

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

3

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

4

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

5

Which sources do blood glucose come from?

- hydrolysis of food
-glycogenolysis
-gluconeogenesis

6

What is blood glucose?

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

7

What does adrenaline do?

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

8

What is the feedback mechanism?

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

9

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