Experimental biochemistry. 2nd edition

Experimental biochemistry. 2nd edition

BIOCHEMICAL EDUCATION January to new graduate students, or to undergraduates in their final year. Each topic for a book is chosen on the basis that ...

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BIOCHEMICAL EDUCATION

January

to new graduate students, or to undergraduates in their final year. Each topic for a book is chosen on the basis that the subject has not already been treated in sufficient detail and depth by standard texts, so that a student is not able to read a specialist review without a good deal of further study. The books in the series are outlines rather than monographs, and this one by C. W. Jones accomplishes its objective most effectively. It will be a great help to students in the categories mentioned, and to teachers attempting to keep up to date in an area outside their own specialities. The main sections are: 1, introduction to bioenergetics; 2, components of the respiratory chain; 3, organization and function of the coupling membrane; 4, the energized state, 5, mechanisms of oxidative phosphorylation; 6, bacterial systems. In section 1, it is assumed that the students understands the elements of thermodynamics, and discussion centers upon the properties of ATP, the "league table" of energy-rich compounds, substrate level and oxidative phosphorylation, and redox aspects of photosynthesis. The small section on pyrophosphate might need modification in the future, since there is growing evidence that its role in metabolism is much more positive than merely to submit to hydrolysis, thereby providing reactions which produce it with a thermodynamic pull to the right. In later sections, I liked the very clear line drawings and diagrams to illustrate mitochondrial structure and function, and translocation of solutes through membranes. In section 5, the main features of the three current hypotheses concerning oxidative phosphoryiation, and the evidence for them are summarized with explanatory diagrams. The student will get, at last, a simple account of issues that have been argued with some heat over the last 20 years. One of the few sentences that caused me to raise my eyebrows was: "The chemiosmotic hypothesis ( 1 9 6 1 ) . . . was immediately viewed as a distinct alternative to the chemical hypothesis". I would add: except by some of the specialists in the area. I recall that Mitchell's advocacy was robust as well as persuasive; and it needed to be. In this book, all the diagrams are clear and uncomplicated, and not a word is wasted in the text; in summary, I gained the overall impression of a perfect set of notes for an excellent sequence of lectures. Dr. Jones has given an outline of present knowledge of how protons and electrons, removed from metabolites, provide energy that is harnessed on their journey to a final rendevous with oxygen.

At a less sophisticated level, Dr Becker describes how energy is u~. A central feature of the operation is the Krehs Cycle which is introduced, as is traditional, in the chapter concerned with aerobic metabolism, whereas giycolysis is dealt with in the section on anaerobic metabolism; and yet, of course, O 2 does not participate directly in either sequence. Indeed, the exclusion of O2 is a striking feature of most metabolic reactions, and I am sure that this would fascinate students who were entirely new to the subject and did not yet exhibit the indifference bred by familiarity. There would be much to be said for an initial historical approach to metabohsm: not through the history of the subject, but through the history of our planet, beginning with the origins of biochemicals. R. E. Dickerson and his colleagues 3 have presented a detailed scheme for the evolution of bacterial energy metabolism in which, amongst many other interesting features, the component reactions of Krebs cycle are seen as having evolved piecemeal in the photosynthetic sulfur bacteria under anaerobic conditions. Thanks to the unique properties of 02 , this essentially anaerobic series of reactions was preserved in living forms throughout the development of our present oxidizing atmosphere, and with this, the ability of heterotrophs to substitute biochemicals as energy sources instead of using sunlight directly. The point I wish to make now is that the continual operation of the carbon cycle (and those for other elements) became an essential feature for the global harnessing of energy by living forms as they evolved. The evolution of higher plants was contingent upon their synthesis of llgnin and other biochemicals; and these would have blocked the cycle had their breakdown not have been provided for by direct incorporation of 0 2 into natural products, catalyzed by the oxygenases of microorganisms. Like glutamine synthetase and GOGAT which I l~ave mentioned, this aspect of biochemisry is an essential, but neglected, component in the complete education of a biologist.

Experimental Biochemistry. 2nd Edition

elementary statistics but these are not included as such in the book. The chapter on techniques covers most of the methods the student is likely to encounter in the laboratory although in some cases no experiments are presented to accompany the theory. The account of adsorption chromatography is thin and only a few lines are devoted to the very important technique of thin layer chromatography which according to the book appears to be a sub-section of partition chromatographyl Ion exchange chromatograPhY in contrast is dealt with in far more detail but only one experiment accompanies this introduction. The inclusion of redundant terms such as lysozyme, isozyme, optical density and phosphatidyl choline is irritating, and should not be used in a modern textbook. It is always a problem when writing a practical text to strike the right balance between relevant theory and experimental details but in the text under review there is an imbalance with too few experiments accompanying the theory. The limited number of experiments may make the book unsuitable for class adoption where teachers may prefer to select from a greater number of experiments. The price at £6.50 is not unreasonable for a modern textbook of this size, and students will find the introductory theory very useful and may wish to purchase a copy even if it is not used directly in their practical course. In spite of these limitations, it is a book that would make a useful addition to the shelves of anyone involved in the planning of biochemistry practical classes. D. T. Hummer

By J o h n M. C l a r k Jr., a n d R o b e r t L. Switzer. Pp. 336. W. H. F r e e m a n a n d C o m p a n y , San Francisco, 1977. £6.50, paperback. This second edition of Experimental Biochemistry is an updated version of the first edition which appeared in 1964. A total of 31 experiments are presented together with a useful amount of introductory theory. The experiments cover a wide range of biochemistry and use material from animals, plants and microorganisms. The diagrams are well drawn and easy to follow and the general layout of material is aesthetically pleasing. As in the first edition, the book contains divisions based on the chemistry of biological molecules; amino acids, proteins and enzymology; carbohydrates; lipids and membranes; nucleic acids; and a final chapter on metabolism. A section on membranes has been added to the lipids chapter and this is welcome in view of the increasing importance of this topic in biochemistry. The second edition also contains a very useful introductory chapter on biochemical techniques which is generally well presented. This section starts with an account of the units of biochemistry which is an extremely important subject that always seems to cause problems to students. In view of this it is a pity that more space is not devoted to this topic. It is also regrettable that SI units are completely ignored. Additional advice could also have been given on how to write up an experiment as it is probably as important to be able to communicate results and ideas to others as it is to be technically competent in carrying out an experiment. A practical text should also introduce the concepts of the accuracy and precision of biochemical measurements, biological variation and

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REFERENCES IDagley, S. (1973) Biochem. Ed. 1, 4. 2Dagiey, S. (1974)Biochem. Ed. 2, 16. 3Dickerson, R. E. Timkovich, R. and Almassy, R. J. (1976)J. Mo/. Biol. 100, 473.

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