16.3

Question 1

hormones

Answer 1

-produced in glands which secrete directly into blood
-carried in blood plasma to target cells
-effective in low concs
-widespread and long-lasting

Question 2

Adrenaline mechanism

Answer 2

-adrenaline binds to protein receptor within csm of liver cell
-causes protein to change shape on inside of membrane
-activates enzyme adenyl cyclase
-ATP converted to cyclic AMP
-cAMP acts as second messenger and binds to protein kinase enzyme, changing its shape and activating it
-active protein kinase enzyme catalyses conversion of glycogen to glucose
-glucose moves out of liver cell by facilitated diffusion into blood

Question 3

pancreas

Answer 3

produces enzymes protease amylase and lipase

produces hormones insulin and glucagon

Question 4

which cells make up pancrease

Answer 4

endocrine cells grouped together into islets of Langerhans

Question 5

a cells

Answer 5

larger and produce glucagon

Question 6

b cells

Answer 6

smaller and produce insulin

Question 7

glycogenesis

Answer 7

conversion of glucose into glycogen

Question 8

glycogenolysis

Answer 8

breakdown of glycogen to glucose

Question 9

gluconeogenesis

Answer 9

production of glucose from sources other than carbohydrates(e.g. glycerol and amino acids)

Question 10

too high blood glucose

Answer 10

lowers water potential of blood
-osmotic problems
-dehydration

Question 11

too low blood glucose

Answer 11

lack of respiration
cells deprived of energy and die

Question 12

3 factors that influence bgc

Answer 12

1. diet
2. hydrolysis in the small intestine of glycogen
3. gluconeogenesis

Question 13

b cells and high bgc

Answer 13

• have receptors that detect stimulus of rise in bgc

-secrete insulin directly into blood

-insulin binds with glycoprotein receptors on csm of red blood cells

-glucose transport carrier proteins change tertiary structure and open, allowing more glucose into cells by facilitated diffusion

-number of glucose carrier proteins increase on csm(vesicles fuse with csm to help)

-activation of enzymes that convert glcose to glycogen and fat

Question 14

lowered bgc

Answer 14

• increases rate of absorption of glucose into cells

-increases respiratory rate of cells

-increase rate of conversion of glucose into glycogen in cells of liver and muscles

-increases rate of conversion of glucose to fat

Question 15

a cells and low bgc

Answer 15

• a cells detect fall in bgc and secrete glucagon into blood

-glucagon attaches to specific protein receptors on csm of liver cells

-activates enzymes that convert glycogen to glucose

-activate enzymes involved in conversion of amino acids and glycerol into glucose

Question 16

adrenaline and bgc

Answer 16

-attaches to protein receptors on csm of target cells

-activates enzymes that causes breakdown of glycogen to glucose in liver