UNIVERSITY OF EAST ANGLIA School of Biological Sciences Main Series UG Examination 2016-17 INVESTIGATION OF HUMAN DISEASE BIO-5016B Time allowed: 2 hours Answer ALL questions in Section A, ALL PARTS of the question from Section B and ONE question from Section C. Write answers to EACH SECTION in the Answer Grid or SEPARATE booklet. The maximum number of marks available for your answers in SECTION A is 40 marks The maximum number of marks available for your answer in SECTION B is 30 marks The maximum number of marks available for your answer in SECTION C is 30 marks The TOTAL number of marks available for the paper is 100 Numbers in square brackets [ ] indicate the relevant mark applied to each part of the question. Notes are not permitted in this examination. Do not turn over until you are told to do so by the Invigilator. BIO-5016B Module Contact: Prof Vince Ellis, BIO Copyright of the University of East Anglia Version 2
2 SECTION A: MULTIPLE CHOICE AND SHORT ANSWER QUESTIONS Answer ALL questions [40 marks] Answer multiple choice questions in the answer grid provided and attach this to your booklet for Section A. Unless stated otherwise all multiple choice questions have ONE answer. 1. Under which of the following conditions does sickle cell haemoglobin form polymers? a) Low concentrations of Fe b) High concentrations of Fe c) Low concentrations of O2 d) High concentrations of O2 e) Under all conditions 2. Methaemoglobin describes haemoglobin with which abnormality? a) Absence of haem group b) Absence of Fe in haem group c) Oxidation of Fe 2+ to Fe 3+ d) Reduction of Fe 3+ to Fe 2+ e) Substitution of Fe for another metal atom 3. How many times has the sickle cell mutation in haemoglobin thought to have arisen? a) Once b) Five times c) Ten times d) Hundreds of times e) It isn t known 4. Which of the following is not an anticoagulant? a) Calcium chloride b) EDTA c) Heparin d) Sodium citrate e) Warfarin Section A continues on next page/...
3 Section A continued... 5. Platelet function can be monitored using which of these tests? a) Activated partial thromboplastin time (aptt) b) Prothrombin time c) Reptilase time d) Skin bleeding time test e) Thrombin time 6. Factor XIIIa, responsible for the cross-linking of fibrin polymers, is which type of enzyme? a) Carboxylase b) Cyclooxygenase c) Oxidoreductase d) Serine protease e) Transglutaminase 7. Which of the following tests is not used for the clinical diagnosis of muscular dystrophies? a) Increased fat tissue b) Increased inflammatory cell infiltration c) Increased levels of albumin d) Increased levels of creatine kinase e) Increased numbers of centrally located nuclei 8. The endogenous stem cell of muscle is the: a) endothelial cell b) epithelial cell c) myoblast d) satellite cell e) smooth muscle cell Section A continues on next page/... TURN OVER
4 Section A continued... For questions 9-11: Complete each of the following three statements using one of the terms below (write your answers in your answer grid, do not write your answers on the exam paper): a) actin b) myosin c) Z-line d) A-band e) I-band 9. A sarcomere is the distance between two. 10. The thicker filaments are the filaments. 11. The myosin filaments are located in the. 12. Marfan s syndrome is due to mutations in which of the following? a) Aggrecan b) Collagen c) Fibrillin d) Fibronectin e) Versican 13. Which one of the following enzymes is essential for collagen fibril formation? a) ADAMTS-2 b) ADAMTS-3 c) ADAMTS-14 d) Pro-collagen C-peptidase e) Pro-collagen N-peptidase 14. Which of the following is the major posttranslational modification involved in stabilising the collagen triple helix? a) Adenylation b) Carboxylation c) Deamidation d) Hydroxylation e) Iodination Section A continues on next page/...
5 Section A continued... 15. Why does the anti-cholinesterase physostigmine improve the symptoms of some patients with myasthenia gravis? a) It promotes neuronal cell death b) It inhibits nicotinic acetylcholine receptors c) It increases availability of acetylcholine at the neuromuscular junction d) It increases availability of glutamate at the neuromuscular junction e) It promotes glutamate re-uptake at the neuromuscular junction 16. The anticonvulsant drugs phenytoin, lamotriginine and carbamazepine act by inhibiting which type of ion channel? a) Calcium-activated chloride channels b) Inward rectifier potassium channels c) Voltage-gated calcium channels d) Voltage-gated potassium channels e) Voltage-gated sodium channels 17. Patients with Liddle s disease have hypertension for which of the following reasons? a) Increased production of aldosterone b) Increased production of angiotensinogen c) Increased Na + reabsorption in the collecting duct d) Decreased Na + reabsorption in the collecting duct e) Decreased K + secretion in the collecting duct 18. Deficiency of the enzyme tyrosine-3 monooxygenase, which is involved in the synthesis of melanin, results in which condition? a) Achromatism b) Albinism c) Cretinism d) Hypothyroidism e) Rheumatism Section A continues on next page/... TURN OVER
6 Section A continued... 19. The hormone thyroxine contains a form of tyrosine that has been coupled to which of the following? a) Calcium b) Copper c) Iodine d) Iron e) Magnesium 20. Which of the following components of low density lipoprotein (LDL) is recognised by the LDL receptor (LDLR)? a) Apolipoprotein B-100 b) Free cholesterol c) Esterified cholesterol d) Phospholipid e) Triacylglycerol For all remaining questions in Section A, please use an answer booklet. Remember to attach your multiple choice answer grid to the booklet. 21. Briefly explain how the Factor V Leiden mutation leads to an increased risk of thrombosis. [5 marks] 22. Briefly, outline the molecular basis for differences in the severity of Osteogenesis Imperfecta. [5 marks] 23. How do the sulphonylurea class of antidiabetic drugs act at pancreatic β-cells to stimulate insulin secretion? [5 marks] 24. Briefly describe the steps involved in the targeting and degradation of proteins in the proteasome complex. [5 marks] END OF SECTION A START YOUR ANSWER TO THE NEXT SECTION IN A NEW BOOKLET Section B begins on next page/...
7 SECTION B: DATA HANDLING QUESTION ANSWER THIS SECTION IN A NEW BOOKLET Answer ALL PARTS of this question. [30 marks] 25. Three patients (A, B and C) presented with symptoms of haemolytic anaemia of varying severity. The haemoglobin protein and its genes were analysed in these patients. Answer each of the questions, in relation to the data shown. The sequence of the β-globin gene of the three patients, and a normal individual was determined. The 5 sequences obtained are shown in Table 1 below. Patient A: ATG GTG CAT CTG ACT CCT AAG GAG AAG TCT GCC GTT ACT GCC CTG TGG GGC AAG GTG Patient B: ATG GTG CAT CTG ACT CCT GAG GAG AAG TCT GCC GTT ACT GCC CTG TGG GGC TAG GTG Patient C: ATG GTG CAT CTG ACT CCT GTG GAG AAG TCT GCC GTT ACT GCC CTG TGG GGC AAG GTG Normal: ATG GTG CAT CTG ACT CCT GAG GAG AAG TCT GCC GTT ACT GCC CTG TGG GGC AAG GTG Table 1: 5 sequence analysis of β-globin gene (a) Analyse these sequences to determine the genetic mutation present in each of the patients (the genetic code is given in Appendix 1). [6 marks] Section B Q25 continues on next page/... TURN OVER
8 Section B Q25 continued... (b) Haemoglobin from the normal individual and patients A and C was analysed by isoelectric focusing electrophoresis. The results are shown in Figure 1 below. Predict which of the samples have been analysed in each of the three lanes, and explain your reasoning. [6 marks] Figure 1: Isoelectric focusing electrophoresis of haemoglobin samples from two of the patients and the normal individual (c) State whether each of the patients is suffering from a haemoglobinopathy or a thalassemia. Explain your reasoning. [6 marks] (d) Explain whether each of the mutations will affect the assembly of the haemoglobin tetramer. Will this be the same in both the adult and the foetus? [6 marks] (e) All three patients have symptoms of haemolytic anaemia, but Patient C also has severe joint pain. Explain the reasons for this difference. [6 marks] END OF SECTION B START YOUR ANSWER TO THE NEXT SECTION IN A NEW BOOKLET Section C begins on next page/...
9 SECTION C: ESSAY QUESTION ANSWER THIS SECTION IN A NEW BOOKLET Answer ONE question [30 marks] 26. Discuss therapeutic strategies to ameliorate severe forms of muscular dystrophy. 27. Explain how mis-sense and nonsense mutations in ion channel genes can give rise to diseases of the cardiovascular, endocrine gland and nervous system. 28. Briefly explain why inborn errors of metabolism are tested for in the NHS Newborn Screening Programme. Using a specific example, explain how our biochemical understanding has led to improved diagnosis, treatment and management of one such condition. END OF PAPER
The Genetic Code UNIVERSITY OF EAST ANGLIA School of Biological Sciences Main Series UG Examination 2016-17 INVESTIGATION OF HUMAN DISEASE BIO-5016B Appendix 1