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Features Section: Problem-Based Learning

Editor: C A Smith, the Manchester Metropoli tan University, UK

One of the abilities all teachers try to instill in their students is the competence to solve problems. This is consistent with the philosophy that education is about being able to do things and not merely the memorising of facts. This, of course, demands the associated skill of knowing how to find information when it is needed. Several issues of Biochemical Education have included articles on problems and problem-solving, 1-5 as well as two separqate problem pages. 6"7 It has, however, been decided that such an important topic as problem-solving, central to much of biochemistry, warrants a regular feature, and in future the Problem Page will be a feature of Biochemical Education. The aims of having a Problem Page as a regular inclusion are (a) to offer teachers a selection of problems which they can use directly or adapt for their own use, and (b) to provide a forum for the discussion of what good problems are - - from what they are intended to test to how much information should be given to students.

Teachers of biochemistry, and in the related disciplines often subsumed into biochemistry (eg cell and molecular biology, biotechnology), 8 usually regard their subject as quantitative and exhort their students to think and express themselves in mathematical terms whenever possible. In any case, students need to be numerate, if only for the most prosaic of reasons such as making up solutions of defined concentration or the interchanging of units. However, problem-solving can and should test other skills. For example, students may be given limited amounts of information from which they can be expected to deduce or develop logical, useful outcomes. Thus they could be asked to suggest ways of isolating cell organelles or macromolecules given some of the properties of each; devise a means of assaying a particular biological molecule given basic laboratory equipment and/or some knowledge of the functions of the molecule or extrapolate or infer some properties of a biological system on the basis of experimental data.

Most of the major teaching textbooks which form the bibles or perhaps the new testaments of biochemistry, molecular biology and cell biology (see references 9-20) recognise and encourage problem-solving skills, often by including relevant sections at the ends of chapters. Also, books devoted to problems have been written as separate problem texts to accompany some of these marvellous textbooks, as well as a number of 'stand alone' problem booksfl t-3° Nonetheless, there is always a shortage of 'good' problems which, in turn, raises the question of what constitutes a good problem.

We invite readers to send in what they consider to be good examples of problems in biochemistry, whatever the

particular area taught, from cell biology to biological chemistry, immunology to biotechnology; and at whatever level, pre-university to taught Masters degree. It might be useful if it was briefly explained what is the context in which the problems are given, eg course, year, tutorial/ examination, etc. Undoubtedly there are an enormous range and number of 'good' examples of problem-setting in the biochemical community from which we can all learn and benefit! By publishing problems we help each other, and by seeing and criticising them we will be able to identify 'good' practices.

Please send your contributions to the editor of Bio- chemical Education in the normal way. I look forward to receiving them. Indeed, the success of the Problems Page depends upon you, the teachers of biochemistry.

References t Carroll, M (1985) Biochem Educ 13, 117- ! 19

2Ploger, D and Harvey, R (1988) Biochem Educ 16, 76-79

3Dawson, A G (1988) Biochem Educ 16, 167-169

4Gubareva, A E, Fedorov, S A, Avdeeva, L A and Aleinicova, T L (1990) Biochem Educ 18, 130-131

SSugiyama, T, Isohashi, F, Higashi, T, Kagamiyama, H, Tagawa, K and Taniguchi, N (1991) Biochem Educ 19, 58-63

6Anonymous (1991) Biochem Educ 19, 199

7Brosemer, R W (1992) Biochem Educ 20, 170

8Campbell, P N (1992) Biochem Educ 20, 158-165

9Lehninger, A L (1975) Biochemistry, Second Edition, Worth Pub- lishers, New York

H~Metzler, D E (1977) Biochemistry, Academic Press, New York

i i Freifelder, D (1983) Molecular Biology, Van Nostrand Reinhold, New York

12 Darnell, J, Lodish, H and Baltimore D (1990) Molecular Cell Biology, Second Edition, Scientific American Books, W H Freeman, New York

13Watson, J D, Hopkins, N H, Roberts, J W, Steizt, J A and Weiner, A M (1987) Molecular Biology of the Gene, Fourth Edition, Benjamin/ Cummings, Menlo Park, CA, USA

~4Stryer, L (1988) Biochemistry, Third Edition, W H Freeman, New York

~SZubay, G (1988) Biochemistry, Second Edition, MacMillan, New York

t6Alberts, B, Bray, D, Lewis, J, Raft, M, Roberts, K and Watson, J D (1989) Molecular Biology of the Cell, Second Edition, Garland, New York

~TMathews, C K and van Holde, K E (1990) Biochemistry, Benjamin/ Cummings, Redwood City, CA, USA

~Voet, D and Voet, J G (1990) Biochemistry, John Wiley & Sons, New York

19Becker, W M and Deamer, D W (1991) The World of the Cell, Second Edition, Benjamin/Cummings, Redwood City, CA, USA

2°Abeles, R H, Frey, P A and Jencks, W P (1992) Biochemistry, Jones and Bartlett, Boston

21 Dawes, E A (1967) Quantitative Problems in Biochemistry, Fourth Edition, Livingstone, Edinburgh

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22Kerridge, D and Tipton, K F (1972) Biochemical Reasoning, W A Benjamin, Menlo Park, CA, USA

23 Montgomery, R and Swenson, C A (1976) Quantitative Problems in the Biochemical Sciences, Second Edition, W H Freeman and Co, San Francisco

24Segel, I H (1976) Biochemical Calculations, Second Edition, John Wiley & Sons, New York

25Armstrong, W G, Reed, F B and Wells, P J (1984) Self-assessment in Biochemisty for Medicine & Dentistry, Blackwell Scientific, Oxford

26O'Sullivan, D G (1986) Pocket Examiner in Biochemistry, Churchill Livingstone, Edinburgh

27Hassall, H, Turner, A J and Wood, E J (1987) Multiple Choice Questions in Biochemistry, Churchill Livingstone, Edinburgh

28Magill, J (1988) Problem-solving in Biochemistry: A Practical Approach, MacMillan, New York

29Wilson, J and Hunt, T (1989) Molecular Biology of the Cell: The Problems Book, Garland, New York

3°Gumport, R I, Jonas, A, Mintel, R, Rhodes, C and Koeppe, R E (1990) Student's Companion to Stryer's Biochemistry, W H Freeman, New York

Drs M M Dawson and I Graham of one of the 'new' universities of the United Kingdom, the Manchester Metro- politan University, have submitted a number of interesting problems in the general field of immunology. Immunology is a subject students of biochemistry find of great interest, whether they are reading biochemistry as a distinct disci- pline or as a supporting subject to another field or in the Biological Sciences generally. Immunology offers scope for a number of types of problems ranging from those in the cell biology field to questions on biological molecules reflecting the increase in the range and complexity which has advanced the subject in recent years

Data Handling Problems in Immunochemistry

MAUREEN M DAWSON and IAN GRAHAM

Department of Biological Sciences The Manchester Metropolitan University, Manchester M1 5GD, UK

Introduction Immunology is a subject of great interest to biology, biochemistry and biomedical science students. In this department, Immunology is taught at several levels on a variety of courses, including HND Applied Biology, HNC Physiological Measurements, HNC Biomedical Sciences, the primary examination of the Fellowship of the Institute of Medical Laboratory Sciences (FIMLS) and BSc (Hons) Applied Biological Sciences, to junior and senior under- graduates. The following are a range of problems which have been written for students over the last few years. We believe that these particular problem questions assess the ability of students to handle and interpret data as well as reinforcing basic immunological knowledge. The questions are purposely designed for different groups and academic levels of student and they complement formal lectures and practical classes in the subject.

We also employ exercises based on 'Case Studies' in which students have to decide which clinical laboratory investigations are most appropriate in particular circum- stances, and exercises in which they decide on an appropriate immunoassay for a given set of conditions. These latter exercises are not presented here, but may be submitted at a later date. We are very happy to supply them to anybody who requests them, and naturally will be delighted to correspond on any of the questions presented as well as receive questions from any readers.

Single Radial Immunodiffusion The single radial immunodiffusion (Mancini) technique was used to measure the level of IgG in the serum of a child who suffered repeated and severe bacterial in- fections. The diameters of precipitin rings were recorded when 10 ~1 of the serum was allowed to diffuse into agar containing an antibody to IgG. The ring diameters were compared with those obtained using known concen- trations of pure IgG, and with serum obtained from a healthy individual. The following results were obtained:

Concentration of standard Diameter (d) of ring (mg/ml) (mm)

0.5 4.5 1.0 6.5 1.5 7.5 2.0 8.9 2.5 9.5 3.0 11.0 Normal serum diluted 1 in 5 9.2 1 in 10 6.4 Patient's serum (undiluted) 4.7

Plot a standard curve of d 2 against IgG concentration. Use this graph to determine the concentration of IgG in the serum of the healthy individual and the patient. What conclusions can be made about the patient's illness? What other investigations could be made to support your conclusions? What treatments can be suggested?

Answers and ancillary notes This exercise is aimed at HND students taking a unit called Cell Biology, Genetics and Immunology in the first year of a two-year course. It can, however, equally be used with first year students on a degree in Biomedical Sciences or Applied Biological Sciences. This is a rela- tively simple exercise involving the graphical analysis of data and the manipulation of units of concentration. The students should reach a simple conclusion, namely that the levels of IgG in the patient's serum are much reduced compared with the healthy control serum; 0.55 mg cm -3 compared with 10.5 mg cm -3. This low level of antibody would explain the increased incidence of bacterial in- fections, which are mainly combated by the humoral

BIOCHEMICAL EDUCATION 21(1) 1993