UNIVERSITY OF EAST ANGLIA School of Biological Sciences Main Series UG Examination 2014-15 FUNDAMENTALS OF CELL BIOLOGY AND BIOCHEMISTRY BIO-4004B Time allowed: 2 hours Answer ALL questions in Section A, ALL PARTS of the question in 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. Graph paper is provided. Notes are not permitted in this examination. Do not turn over until you are told to do so by the Invigilator. BIO-4004B Module Contact: Dr Helen James, BIO Copyright of the University of East Anglia Version 1
2 SECTION A: MULTIPLE CHOICE AND SHORT ANSWER QUESTIONS Answer ALL questions. Answer multiple choice questions in the answer grid provided and attach this to your booklet for Section A. 1. In the hierarchy of protein structure which of the following terms is used when referring to the structure that results from assembled subunits? a) Tertiary structure b) Elementary structure c) Primary structure d) Secondary structure e) Quaternary structure 2. Which of the following statements is not an advantage of the cooperative binding of O2 to haemoglobin? a) Haemoglobin is reluctant to take up O2 at first; its affinity increases with O2 uptake b) Allows efficient transfer of O2 from blood to muscle c) In the lungs haemoglobin is saturated with O2 d) In peripheral tissue haemoglobin gives up nearly half of its O2 e) Structural changes in the haemoglobin are permanent 3. The initial velocity of an enzyme catalysed reaction: a) is independent of enzyme concentration b) typically has units of mg ml -1 c) is equal to KM d) typically has units of M s -1 e) is independent of temperature 4. The main component of the bacterial cell wall is a 3D polymer of: a) oligosaccharide b) lipoprotein c) peptidoglycan d) phospholipids e) sterols Section A continues on next page/...
3 Section A continued... 5. Which technique uses antibodies to identify and localise proteins within cells? a) Western Blotting b) Immuno-labelling c) Immuno-precipitation d) Gel electrophoresis e) Electron microscopy 6. What is the function of the centrosome? a) Replicates DNA b) Nucleates actin filaments c) Organises ribosomes d) Nucleates and organises microtubules e) Protects the ends of the chromosomes 7. Which of the following components cannot be transported via gap junctions? a) ATP b) Glucose c) Mg 2+ ions d) Cytochrome C e) camp 8. Which of these statements about the protein domains of the extracellular matrix proteins is not correct? a) They share conserved secondary structures b) They have identical primary structures (sequences) c) There is an evolutionary relationship between them d) Extracellular matrix proteins may contain multiple domains e) Domains can often fold independently of the rest of the protein Section A continues on next page/... TURN OVER
4 Section A continued... 9. The disease Scurvy is caused by: a) reduced gene expression of all collagens b) decreased degradation of collagens c) increased levels of posttranslational processing d) lack of ascorbic acid e) mutations in collagen I genes 10. The Leukocyte rolling of an endothelial cell is mediated by which group of molecules? a) Dystrophins b) Surface proteoglycans c) Cadherins d) Integrin receptors e) Selectins 11. The motility of cellular cilia depends on the presence of which structural element? a) Keratin filaments b) Microtubules c) Actin stress fibers d) Linkage to dystrophin e) Vimentin 12. What is the name given to protein transporters that carry molecules and the cotransported ion in the same direction across a membrane? a) Aquaporins b) Symporters c) Channel proteins d) ABC transporters e) Antiporter 13. During which phase of mitosis does cytoplasmic division occur? a) Metaphase b) Cytokinesis c) Telophase d) G2 e) prophase Section A continues on next page/...
5 Section A continued... 14. Which of the following is not a second messenger? a) Cyclic AMP b) Cyclic GMP c) Diacylglycerol d) Insulin e) Calcium ions 15. Which of the following species is a standard model organism for plant biology studies? a) Drosophila melanogaster b) Mus musculus c) Xenopus laevis d) Escherichia coli e) Arabidopsis thaliana 16. Which of the following is not a carbohydrate? a) Ribose b) Glycine c) Starch d) Glyceraldehyde e) Cellulose 17. Which of the following is a tough, fibrous water insoluble substance found in the cell walls of plants? a) Cellulose b) Amylopectin c) Glycogen d) Chitin e) Amylose Section A continues on next page/... TURN OVER
6 Section A continued... 18. Which statement below is not true of the pyruvate dehydrogenase complex? a) It is located in the mitochondrial matrix b) Acetyl-CoA is one of its products c) It is an enzyme of the citric acid cycle d) CO2 is one of its products e) NAD + is one of its substrates 19. An enzyme used in both glycolysis and gluconeogenesis is: a) 3-phosphoglycerate kinase b) glucose 6-phosphatase c) hexokinase d) phosphofructokinase-1 e) pyruvate kinase 20. Carnitine is: a) a 15-carbon fatty acid b) an essential cofactor for the citric acid cycle c) essential for intracellular transport of fatty acids d) one of the amino acids commonly found in proteins e) present only in carnivorous animals For all remaining questions in Section A, please use an answer booklet. Remember to attach your multiple choice answer grid to the booklet. 21. Fill in the missing words ((a) (d)) in the following statement that would accurately complete the paragraph. (Write your answers in your answer booklet, do not write your answers on the exam paper.) [4 marks] In preparation for separating proteins by chromatography an appropriate column is first (a) with a solution of the same composition as the sample of proteins. The sample of proteins is then (b) on to the column. During this stage of anion exchange chromatography proteins with (c) charge will bind to the column. These proteins are eluted by increasing the concentration of (d) in the solution flowing through the column. Section A continues on next page/...
7 Section A continued... 22. Briefly, what are the main components of membranes and how are membranes structured? [4 marks] 23. Generally, hormones that are peptides act faster than those that are steroids. Using brief notes, explain why this is true. [4 marks] 24. Give four differences between prokaryote and eukaryote cells. [4 marks] 25. What are the two main proteins involved in muscle contraction and briefly how are they involved in the contraction process? [4 marks] END OF SECTION A START YOUR ANSWER TO THE NEXT SECTION IN A NEW BOOKLET Section B begins on next page/... TURN OVER
8 SECTION B: DATA HANDLING QUESTION Answer ALL PARTS of this question [30 marks] 26. Hexokinase catalyses the reaction shown below: ATP + D-hexose ADP + D-hexose 6-phosphate A series of assays were performed to assess the effect of substrate concentration on the activity of hexokinase and the results are presented in Table 1. The total volume of the assay solution was 4 ml and it contained 0.25 M hexokinase and 50 M ATP. Concentration of D-hexose (mm) Initial Velocity (mm min -1 ) 0 0 20 2.86 40 4.44 80 6.15 160 7.62 320 8.65 640 9.28 Table 1. Initial velocities of the hexokinase catalysed phosphorylation of D- hexose. (a) Define what an enzyme is. [2 marks] (b) Draw a Lineweaver-Burk plot for the results in Table 1 on the graph paper provided. [12 marks] (c) Determine KM and Vmax for the enzyme hexokinase. Give KM in units of mm and Vmax in units of mm min -1. [8 marks] (d) Determine the turnover number (kcat) for hexokinase in units of min -1. [5 marks] (e) Define an uncompetitive inhibitor in terms of its effect on KM and Vmax. [3 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 ONE question [30 marks] 27. Various combinations of four major cell-cell adhesion complexes can be found in different cells. Describe their specific functions and define their roles in the tissue context. Use adequate example(s) to support your statements. 28. Compare and contrast photophosphorylation and oxidative phosphorylation. 29. Using examples, describe how cellular communication is achieved in flowering plants over short and long distances. END OF PAPER
UNIVERSITY OF EAST ANGLIA School of Biological Sciences Main Series UG Examination 2014-15 FUNDAMENTALS OF CELL BIOLOGY AND BIOCHEMISTRY BIO-4004B Registration Number SECTION A: Answer Grid (for Multiple Choice Questions only) Place a single cross in the appropriate box Question No. A B C D E Marks given Marks available 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 1 13 1 14 1 15 1 16 1 17 1 18 1 19 1 20 1
11 BIO-4004B EXAMINATION MARKERS 2014-15 [Do not print this when printing to take to Examinations Office! This is for our information only.] Question No. 1 st Marker 2 nd Marker Section A Q1 Helen James Gabriella Kelemen 25 Section B Q26 Helen James Kay Yeoman Section C Q27 Ernst Poschl Mette Mogensen Section C Q28 Julea Butt Richard Bowater Section C Q29 Colwyn Thomas Andrew Chantry