48

Bacitlus

S, cerevisiae

hila

Mb. fornlicicum

Figure 4 Phylogenetic tree constructed using matrix o f sequence differences derived from G A P D H alignment. The tree was constructed manually using branch lengths related to the degree o f difference between the sequences. The angles between the branches are arbitrary, assigned simply to make the viewing o f the diagram easier

bacterial and eucaryal sources which are interrelated. From this observation, it is clear that G A P D H would not be a useful molecular clock for comparing organisms from all three domains although it could be used for bacterial and eucaryal trees.

References 1Fothergill-Gilmore, L A (1991) 'The evolution of RNA and proteins as biocatalysts,' in Fundamentals of Medical Cell Biology, by Bittar, E E (editor) Vol 1, Evolutionary biology, JAI Press, London, pp 163- 188

2FothergilI-Gilmore, L A and Michels, P A M (1992) 'Evolution of glycolysis,' Prog Biophys Mol Biol (in the press)

3Rivera, M C and Lake, J A (1992) Science 257, 74-76 4Woese, C R, Kandler, O and Wheelis, M L (1990) Proc NatlAcad Sci,

USA 87, 4576-4579 5Higgins, D G and Sharp, P M (1988) Gene 73,237-244 ~Doolittle, R F (1986) 'Of Urfs and Orfs: A Primer on How to Analyse Derived Amino Acid Sequences,' University Science Books, Mill Valley, California

7Fabry, S, Heppner, P, Dietmaier, W and Hensel, R (1990) Gene 91, 19-25

8 Potter, S and Fothergill-Gilmore, L A (1992) FEMS Microbiol Lett 94, 235-240

9Hensel, R, Zwickl, P, Fabry, S, Lang, J and Palm, P (1989) Can J Microbiol 35, 81-85

l°Danson, M J (1988) Adv Microb Physiol 29, 165-231 ix Moller-Zinkham, D et al (1989) Arch Microbiol 152,362-367

Book Reviews

1992 Supplement to Biochemistry

D o n a l d V o e t and Jud i th G Voe t . pp 73. John Wi ley and Sons , N e w Y o r k . 1992. $2.95/£1.95 0 - 4 7 1 - 5 7 9 4 4 - 0

Is it worth while to review a slim volume that costs only a nominal sum? In the present case, the novel objective and unusual character of the book raise questions of general interest to teachers of biochemistry that merit analysis. The authors of a successful textbook are to be commended for seeking a novel solution to the problem of preventing their efforts from suffering

rapid obsolescence. I wish that I could conclude that they have succeeded.

The first question concerns the technical problem of integrat- ing new information so that readers are necessarily aware of additions and alterations. There might be several ways to approach this problem, including an index to the supplement, references to specific paragraphs in the original text, or a list of relationships. Since none of these exists, it is difficult to imagine how they might work and I am left with the feeling that students are not likely to integrate supplementary material easily as they use the text either as a primary source of information or as a reference.

In the introduction to the second supplement to their textbook, Donald and Judith Voet emphasize the importance of students and teachers keeping up with the literature. However, they do not make it clear whether the supplement is intended primarily for new students, who should be introduced to new information and recent articles as part of their first course in biochemistry, or whether it is intended for students who have completed their courses and are encouraged to update their texts so that the familiar book need not be replaced by more modern editions. Attempts by this reviewer to relate the supplementary material to the original text leave considerable doubt whether either purpose is served. Although I agree with the importance of students and practitioners of biochemistry surveying the literature regularly and familiarizing themselves with relevant items, I believe that the selection of relevant literature is highly personal and must be done individually as a function of professional interests. Therefore, my comments deal only with the supplement as a manual to be used together with the textbook during an introductory course in biochemistry.

It should be noted that the supplement contains brief discussions of information from current literature but that much of the supplement consists of mere references to review articles and primary papers. The 90 items selected for discussion average less than 3 per chapter; no additional text is given for 10 of the chapters and 11 of the items are related to the chapter on eukaryotic gene expression. In addition to this material, 199 references are listed as suggested reading for 25 of the 34 chapters. Do these references selected from perhaps 10 000 articles that appear each year in major biochemical journals represent basic information that would be likely to be included in a new text? The examples below suggest that the selection reflects the interests of the authors in structure-function relation- ships and that the items that have caught their fancies are presented in much greater detail than similar items are discussed in the original text.

Striking evidence of the personal interests of the authors is the fact that 40 of the 90 topics elaborated in the supplement are based on X-ray crystallography. There is no question of the value of this technology to elucidation of many problems of great current interest to active investigators in many areas of biochemistry. It would be a gross exaggeration, however, to maintain the enthusiasm that greeted David Phillips' study of lysozyme with the belief that the power of X-rays had made other aspects fo enzymology obsolete. One paper that is included deals with the fact that the core protein of the Sindbis virus is a serine protease. Since the virus is not described in either the original text or the supplement, the context of the information is obscure. It is also not clear why this serine protease is particularly worthy of addition to the 13 diverse members listed in the original text.

The only item presented as an advance in amino acid metabolism is an elaborate discussion of the mechanism by which chloroquine acts to kill the plasmodia that cause malaria. Although the studies do present new information in the way these organisms metabolize heine, it is doubtful that such a unique reaction is typical of the sort of information that should be included in any textbook.

B I O C H E M I C A L E D U C A T I O N 21(1) 1993

49

It is possible to question in a similar fashion almost all of the items selected for this supplement. That is, regardless of potential interest of a finding, the very technical presentations of the supplement are dissimilar to the presentations of the original text. In the textbook, PCR is summarized in about 340 words; of the myriad of papers extending and applying PCR technology, one was selected for the supplement based on the observation that certain single-stranded DNA sequences specifically bind to thrombin. Certainly to many biochemists this is an interesting observation and the practical implications are also real. I must ask, however, whether these are the criteria to be used in selecting material for an introduction to biochemistry?

Although the authors could certainly defend their selections of interesting findings from the current literature, I doubt that any consensus could be reached even among other authors of textbooks about which are the fundamental findings that belong in a general description of the field. A growing criticism of our students is that overload of information has made them weak on fundamental understanding, which perhaps should lead us to set more modest goals for introductory courses and their textbooks, to concentrate more on the well established fundamental knowledge upon which modern research is based, to find ways to make this knowledge useful, and to leave the current literature for advanced courses and individual study.

Alan H Mehler

Chemistry and the Living Organism (Fifth Edition)

By M o l l y M Bloomf i e ld , pp 758, John Wi ley , New York . 1992. £21.50 ISBN 0 - 4 7 1 - 5 1 2 9 2 - 3

This is a junior college level text that goes all the way from basic chemical principles, through organic chemistry, to elementary biochemistry. The emphasis is strongly towards the relationship of these topics with humans. Each chapter starts off with a 'human' case history which will surely interest students. (Photo- synthesis on the other hand only gets about threequarters of a page). The aim is to make the chemistry interesting and attractive, rather than hard, and I think the author succeeds. There are going to be many students in the position of wanting to do some chemistry but being frightened off by the perceived difficulty. The book would presumably also appeal to college, pre-med students. The interest and attraction are maintained through frequent 'Perspective Boxes' (eg on the Turin Shroud). I am less happy about the treatment and organisation of the biochemistry section.

The first half of the book deals with chemistry - - atomic structure, gas laws, radioactivity, kinetics - - and this is followed by an elementary but sufficiently detailed account of organic chemistry. This latter story is told from the life scientist's point of view. All too often chemistry is taught to biochemists or potential biochemists by chemists who think that the kinetics of the nitration of aromatic compounds is vital for a good understanding of chemistry. It may be, but unfortunately, they only succeed in putting the students off.

The 'Compounds of Life' starts at p 501 and deals with carbohydrates, lipids and proteins (but not nucleic acids) from the chemical point of view. The treatment is satisfactory but I thought that more could have been done to illuminate the importance of macromolecules and membranes.

This section is followed by a chapter on enzymes, vitamins and hormones (grouped together) and the biological emphasis is more apparent here. Finally, nucleic acids and protein synthesis are dealt with in the last chapter (p 668). Thus the approach is rather ' traditional ' and the biochemistry somewhat abbreviated. Presumably this reflects the needs of the market to which the book is aimed.

In addition there are appendices (eg on using significant figures), and an extensive glossary. Each chapter is followed by reasonably imaginative problems ('review' type, 'study' type and ' integrative' type) and there are in-text examples. Each chapter also has learning objectives ("By the time you have finished this chapter you should be able to: write, define, c a l c u l a t e . . , etc.) Also available are a Student Study Guide, a Laboratory Manual, and a Teacher's Manual, but I have not seen these.

Overall, an attractive production, quite interesting and easy to read. Worth a look at if the students you have to deal with are at this borderline level between high school and university.

E J Wood

Biosynthesis and the Integration of Cell Metabolism

' B i o t e c h n o l o g y by O p e n Lea rn ing Ser ies ' pp 257. But te r - w o r t h - H e i n c m a n n , Oxford . 1992. £19.95

ISBN 0 - 7 5 0 6 - 1 1 5 0 6 - 0

This book is a component member of the Biotechnology by Open Learning Series which is aimed at students at universities, polytechnics and colleges, as well as industrial organisations and professional bodies. This text is one of three which are devoted to increasing our understanding of intermediary metabolism (a phrase used here to describe the chemical reactions within cells which produce the basic building blocks necessary for the manufacture of cellular components).

The first chapter introduces the reader to the design of an open learning text and also refreshes the reader's knowledge of the prerequisites for biosynthesis to occur which are described in greater detail in the previous two tests. The second chapter describes the nutritional requirements of cells and the mechan- ism for uptake of these nutrients into the cells. The next four chapters concentrate on the assimilation of nitrogen and sulphur and the biosynthesis of amino acids, nucleotides, lipids and carbohydrates. The final two chapters outline the integration, regulation and control of metabolic pathways.

The text is kept simple and is easy to understand. The left hand margin of each page contains key phrases and words summarising the text. There is also space for personal notes which the use of an open learning text is encouraged to make. Each chapter ends with a summary and a list of objectives which the reader should now be able to complete having read the appropriate chapter. One may wonder why the objectives did not come at the beginning. However, the text sadly lacks the benefits of the use of colour and different font types which are used to enhance most modern textbooks. For example, no efforts are made to distinguish enzymes from substrates or reaction products, or to highlight important points. The dia- grams are also very sparse and no references are given should the reader wish to pursue any of the topics further.

The open learning series is designed so that the reader "interacts" with the text. The text is interspersed with activities and self-assessment questions which give the reader an idea of the knowledge he or she should have gained by reading the relevant chapter. Although these attempt to focus the reader on the text, some students may find these questions somewhat superfluous and irritating at times. For example, "this chapter has introduced a lot of new c o m p o u n d s . . , many are referred to by initials, it is obviously important to remember t h e s e . . , and there is a special prize if you can get the last one right".

Overall this book gives a clear and concise understanding of the principles involved in the biosynthesis of cellular building blocks and might act as a useful revision aid. However, there are better textbooks available for a similar price which make good

B I O C H E M I C A L E D U C A T I O N 21(1) 1993