The Enzyme Kinetics of Polyphenol Oxidase

90 home, is obligatory although not all the students realize the importance of the latter. The experiments in the laboratory courses are designed to supplement the fundamental teaching. In general, every student out of the 450 has to do individually, or in groups of two, the experiments listed in Table 1. The courses include analyses of unknown samples and the writing of detailed laboratory protocols. In the course of the second year the students have to pass five tests in biochemistry (two oral and three written exercises). In addition they have to prepare three essays in which the results and the protocols of selected laboratory experiments have to be connected with theoretical aspects provided by the lectures, seminars and textbooks. This turns out to be a profitable way of co-ordinating the three different kinds of tuition. Human biochemistry teaching in the second half-year is carefully synchronized with physiology teaching and is vertically co-ordinated witl~ pathological biochemistry, clinical biochemistry, immunology, human genetics and general pathology, all of which are taught in the third year. At the end of the second year (thirty-three academic weeks) the students have to pass the final examinations in biochemistry, physiology and anatomy within a period of four weeks. The examinations are principally oral (four students per group) and are taken separately in the three fields. In biochemistry the examination lasts four hours. Under supervision of an instructor the students have to perform two experiments (the experimental details and the instructions for operation of the instruments such as pH meter, photometer, polarimeter, etc, are at the students' disposal) including a short protocol. This is followed by an oral examination by the professors or by one of the senior lecturers. The final mark results largely from the performance of the student in this examination: however his work during the whole year is also taken into account, usually to the advantage of the student. Despite a certain degree of success a number of problems remain to be solved, some of them being attributable to the fact that in our system the second year is heavily loaded by anatomy, physiology and biochemistry. Each discipline takes up a great deal of the students' time, although the teaching staff in the three fields are in continuous contact in order to co-ordinate the demands upon the students and to devise realistic workloads and timetables. Co-operation with students as members of a staff-student committee has proved to be very useful in this respect. In previous times it was difficult to co-ordinate preclinical and clinical fields. However with the inception of courses in pathological biochemistry, pathological physiology, medical genetics, and clinical immunology, vertical co-operation and co-ordination has become easier to the advantage of the students' training. In our experience, oral tests and written exercises during the year are really important in stimulating the students to undertake continuous learning. The practical courses are considered integral parts of the teaching system and indeed we are convinced that supplementation of the theory with selected experiments and practise in manual work is valuable for the future physician. The training of students to make precise observations and reach critical conclusions, and the engendering of creativity and honesty, as well as the preparing of realistic protocols cannot be substituted by other kinds of tuition.

Content of lectures The content and the organization of the lectures is under continuous discussion, and some of the questions considered are as follows. Should factual documentation or the discussion of concepts be preferred? To what extent should historical aspects be included in the systematics of the presentation. Should the lectures present minimum knowledge or should they go beyond it? Should controversies and 'hot lines' in current research be included or should the lectures at this level of education be confined to consolidated knowledge? I believe that the answers to these questions depend mainly on the qualifications and the pedagogic skill of the BIOCHEMICAL EDUCATION

8(3)

1980

lecturer: there is no standard answer. Before concepts and correlations can be understood by the students they must have assimilated a certain number of selected facts. In the selection of these ti~e educational goal has to be carefully determined. Many years ago we stopped attempting to familiarize the students with the history of biochemistry in a systematic way, but we continue to deal with the historic evolution of selected problems and their stepwise solution by including the contributions of past and present outstanding biochemists and molecular biologists. We hold the view that the lectures should go beyond the minimum knowledge demanded but should emphasize crucial points indispensable for students. In selected and instructive cases the lecture should follow the way of research in the formulation and solution of important questions. Criteria for selection of such topics should be: value in terms of contribution to fundamental knowledge, or medical application, or training in interdisciplinary thinking. We do include controversial matters in the lectures if the)" are instructive and do not try to avoid explaining contradictory points of view in current and past research. Here too we prefer fields which are either of basic importance, or are of significance in interdisciplinary education. Of course, teaching of consolidated knowledge is at the centre of our lectures: however we consider it to be one of our most important obligations as academic teachers to give students a vivid picture of present-day science and to produce and strengthen an open and critical attitude of mind in the young generation entrusted to us. References 1Kornberg, A (1978) TIBS, April N73-N74 2Schwartz, P L (1979)TIBS, April N85 3Murray, W C (1979)BiochemicalEducation7, 77-78 4Newsholme,E A (1979) TIBS, August N188-N189 SSchambye,P (1979)TIBS, August N189-N190 *Rapoport, S (1977) Medizinische Biochemie, 7 Auflage. VEB Verlag Volk and Gesundheit Berlin 7Hofmann,E (1979)DynamischeBiochemie,4 Auflage.Akademie-VerlagBerlin 8Hofmann, E (1980) Funktionelle Biochemiedes Menschen, 2 Auflage. AkademieVerlag Berlin

Monitor in Brief Bryce, C F A and Stewart A M, The Application of Random-Access Back Projection in Computer-AssistedInstruction, Aspects of Educational Techology, vol XIII, 245-251 (1979). Edited by G T Page and Q Whitlock. Kogan Page, London. Random-access back projection, interfaced to a main frame computer, was investigated as a means of generating supportive visual material for structured interactive computer-assisted learning packages in biochemistry. Detailed aspects of the associated software and hardware of the unit are discussed. Devine, J E and Presant, L P, The Enzyme Kinetics ofPolyphenol Oxidase, J Coil ScienceTeaching 8,226-228 (1979). The extraction of polyphenol oxidase from potatoes is described together with a protocol for studying the pH optimum of the enzyme. The authors claim that the procedures are highly reproducible and, in their present form, are essentially 'student-proof'. This enzyme exhibits a pHop, of 5 so could be usefully used with, eg salivary amylase(pHopt 'x, 7) and alkaline phosphatase (pHopt ix, 10) to demonstrate the variation that can occur in this parameter. Fox, J L, Computer Imaging Enhances Molecular Shape, Chemical and Engineering News 57, 22-27 (1979). This serves as a useful review of the way in which computers are currently" being used to help in the X-ray crystallographic study of biological macromolecules. The article considers topics such as data handling and refinement and computer graphics (including dynamic graphics) with frequent reference to named examples like the IgG antibody molecule, serine proteases, etc.