16

Question 1

Diabetes- control by diet (2+4)

Answer 1

type 1- eating regularly, control carbohydrate intake

type 2- reduced sugar intake, lose weight, more exercise, reduced fat intake

Question 2

diabetes- control by insulin (of 1 /2)

Answer 2

type 1- injections of insulin- dose of insulin matched to g intake
type 2-use of drugs that target insulin receptors= more g uptake by cells

Question 3

cause of type 1 vs type 2 diabetes=

Answer 3

1- gene mutation

2-poor diet/lack of exercise/obesity

Question 4

Secondary messenger model- process

Answer 4

1) a/glucagon bind to specific complementary receptors on c-m of liver cells
2) Activate adenylate cyclase
3) converts ATP> cyclic AMP (cAMP)
4) cAMP activates protein kinase A
5) Protein kinase A activates cascade of reactions to break down glycogen> glucose (GLYCOGENOLYSIS)

Question 5

Role of adrenaline

Answer 5

1) Adrenaline secreted by adrenal glands if blood glucose conc is low/ stressed/ exercising
2) Binds to specific receptors on c-s-m of liver cells
3) This activates enzymes involved in glycogen>glucose, GLYCOGENOLYSIS & INHIBITS GLYCOGENESIS
4) Activates secretion of Glucagon from pancreas
5) Overall blood glucose conc INCREASES

Question 6

Action of Glucagon=

Answer 6

1) Glucagon secreted by alpha-cells in ISLETS OF LANGERHANS, in pancreas, when blood glucose conc TOO low
2) Binds to specific receptors on c-s-m of liver cells (tc)
3) Liver cells activate enzymes involved in converting glycogen> glucose, via GLYCOGENOLYSIS
4) also causes activation of enzymes involved in converting glycerol> glucose via GLUCONEOGENESIS
5) glucose conc increases

Question 7

action of insulin=

Answer 7

1) insulin secreted by BETA cells in ISLETS OF LANGERHANS, in pancreas when blood glucose conc too HIGH
2) Insulin binds to specific receptors on c-s-m of liver/muscle cells
3) muscle cells insert more glucose channel proteins in c-m, causing: rate of uptake of g from b by muscle cells to increase
4) activation of enzymes in liver cells that convert glucose> glycogen via GLYCOGENESIS. (Glycogen stored in lc cytoplasm)
5) RoR of glucose increases
Overall decrease in blood glucose conc

Question 8

factors influencing blood glucose conc

Answer 8

• eating food containing carbohydrates

- exercise (increases ROR of glucose)

Question 9

Positive feedback

Answer 9

amplifies change from normal level

advantage= rapidly activate something

Question 10

negative feedback=

Answer 10

• Receptors detect levels too h/l & effectors respond to counteract change
• Restore level to normal

Question 11

homeostasis principles=

Answer 11

1) importance of maintaining core temp & blood pH= enzymes have optimum temp (if too l= not enough ek so fewer collisions & E-S complexes, if too h= enzymes denatures as H bonds in TS break, AS changes shape (fewer E-S complexes)
2) importance of maintaining stable blood glucose conc= enzymes have optimum pH (if too l/h= enzymes denature as ionic bonds in TS break, AS changes shape & no longer complementary (so fewer E-S complexes)
3) importance of maintaining stable blood glucose conc= if too low- not enough glucose for R so less ATP produced & AT cant happen, if too high- blood has low WP, water lost from tissue to blood by osmosis, kidney cant absorb glucose> more water lose in urine, causing DEHYDRATION