5.2 insulin & glucagon

Question 1

where is insulin produced?

Answer 1

Beta cells in the islets of langerhan

Question 2

when is insulin produced?

Answer 2

when blood glucose levels are too high

Question 3

at what point are blood glucose levels too high?

Answer 3

over 90cm mg-3

Question 4

what do beta cells detect?

Answer 4

rises in blood glucose levels

Question 5

where do beta cells secrete insulin?

Answer 5

into the bloodstream

Question 6

virtually all body cells have receptors for insulin, which body cells don’t?

Answer 6

red blood cells

they have no organelles

Question 7

what type of receptor does insulin bind to?

Answer 7

glycoprotein receptor

Question 8

what does insulin cause when it binds to the glycoprotein receptor? what effect does it have?

Answer 8

causes change in tertiary structure of glucose transporter protein channels
allows more glucose in

Question 9

insulin lowers blood glucose by increasing absorption in what?

Answer 9

cells

Question 10

insulin lowers blood glucose by increasing what else in cells?

Answer 10

respiration

Question 11

insulin also lowers blood glucose levels by increasing the rate of which G?

Answer 11

glycogenesis

Question 12

what is glycogenesis?

Answer 12

converting excess glucose into glycogen to be stored in liver

Question 13

insulin lowers blood glucose by increasing conversion of what?

Answer 13

glucose to fat

Question 14

insulin lowers blood glucose by inhibiting the release of what?

Answer 14

glucagon

Question 15

where is glucagon produced?

Answer 15

alpha cells of the islets of langerhan

Question 16

when is glucagon produced?

Answer 16

when blood glucose levels fall

Question 17

where do alpha cells secrete glucagon?

Answer 17

into the blood stream

Question 18

which cells have glucagon receptors?

Answer 18

liver and fat cells

Question 19

glucagon raises blood sugar by breaking down glycogen, what is this?

Answer 19

glycogenolysis

Question 20

glucagon also increases gluconeogenesis, what is this?

Answer 20

producing glucose from non carbohydrate sources e.g. lipids and amino acids, then releasing it into the blood stream

Question 21

what does negative feedback ensure?

Answer 21

changes are reversed and returned back to a set level