5.4.5 diabetes

Question 1

diabetes mellitus

Answer 1

condition where blood glucose concentrations cannot be controlled effectively

Question 2

stem cells

Answer 2

unspecialised cells which have potential to develop into any type of cell

Question 3

what can diabetes mellitus lead to

Answer 3

hypoglycaemia or hyperglycaemia

Question 4

describe type 1 diabetes

Answer 4

(insulin-dependent diabetes)
- usually starts in childhood
- result of autoimmune response where body’s immune system attacks/destroys beta cells
- may also result from viral attack
- cannot synthesise sufficient insulin or store excess glucose as glycogen

Question 5

describe type 2 diabetes

Answer 5

(non-insulin-dependent diabetes)
- produces insulin but not enough
- as people age, responsiveness to insulin declines
- blood glucose concentration almost permanently raised = damage major organs & circulation

Question 6

factors which can cause early onset type 2 diabetes

Answer 6

• obesity
• lack of regular exercise
• high sugar diet (esp. refined sugars)
• being of asian/afro-carribean descent
• family history

Question 7

ways to treat type 1 diabetes

Answer 7

• insulin injections
• insulin pump therapy
• islet cell transplant
• pancreas transplant
• stem cells to grow new islets of Langerhans in pancreas

Question 8

describe insulin pump therapy

Answer 8

small device constantly pumps insulin (controlled rate) into bloodstream via needle inserted permanently under skin

Question 9

describe islet cell transplantation

Answer 9

healthy beta cells from pancreas of deceased doner implanted into pancreas

Question 10

sources of stem cells

Answer 10

• bone marrow
• placenta
• recent research shows precursor cells from in pancreas of adult mice

Question 11

treatment of type 2 diabetes

Answer 11

• lifestyle changes eg. lose weight, regular exercise, monitor diet
• monitor carbohydrate intake
  —> may be supplemented by medication which reduces amount of glucose the liver releases/boosts amount if insulin released from pancreas
• severe cases: insulin injections & other drugs which slow absorption of glucose from digestive system

Question 12

source of insulin

Answer 12

• historically = extracted from pancreas of animals eg pigs, sheep
• recently = produced by E.coli bacteria which have undergone genetic modification to manufacture human insulin

Question 13

advantages of using insulin from genetically modified bacteria

Answer 13

• exact copy of human insulin thus, acts faster & more effective
• less chance of developing tolerance to insulin
• less chance of rejection due to immune response
• lower risk of infection
• cheaper to manufacture insulin than to extract from animals
• manufacturing process is more adaptable to demand
• some people less likely to have moral objections to insulin produced from bacteria than using that extracted from animals