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unproductively 'browsing', rather than 'hunting' for information. The tendency for passive browsing may be offset by the value of animations of dynamic processes and the ability to make non-sequential associations. Often one topic area contains a wealth of information relevant to another area, and assisting students to find these links should enable them to get a better view of 'the whole picture'. There are few places where input is required from the user (other than deciding where to look next), for example to access an animation of affinity chromatog- raphy a user must first correctly identify buffer and sample solutions.

It has been hard to find complaint with the package. Some minor bugs and errors (eg typographical errors) were detected but on the whole the information screens are excellently presented. The screens have a clear layout with high quality graphics, and the text components are generally clear and concise. A minor criticism is that in some places the text is rather small. This could potentially cause problems with users with less than perfect vision. The animations are generally well presented and help to clearly convey concepts by presenting dynamic and temporal sequences which are difficult to explain with static visual material. The diagrams have been simplified to clarify the processes addressed, while the user is directed to the textbook for structurally accurate infor- mation such as electron micrographs. Many of the animations include a number of pauses so that users may proceed at their own pace. The animation may be continued by clicking the left mouse button or exited by pressing the right mouse button (an undocumented feature). However an animation may only be played from start to end in sequence. It would be useful to include animation controls present in earlier versions of Hyper- CE LL (viz start, stop, jump forward/backward). I found it was possible to leave a section with an animation still running, which led to unpredictable results. In most cases I found the animations to be particularly informative. However, there was one exception. Glucose transport into red blood cells has been animated over a range of glucose concentrations from 1 to 10 raM. I am not sure that running the animations presented showing different speeds of transport at different concentrations would be helpful to students, as viewing more than one animation did not seem to provide much additional information.

While the use of a personalised guide disk is a good idea, it imposes some cost by considerably slowing down responses from the program from time to time when the floppy disk is accessed. Perhaps this could be improved by providing a system allowing individual student guide files to be created on a hard disk by the system administrator, although this would complicate administration and logging in to the software.

While all of the sections were reasonably up to date and comprehensive I was particularly impressed by sections on protein synthesis and secretion, the cell cycle and the membrane permeability and transport. The techniques section was also informative, providing insights into a

number of techniques through three simulated problems in protein purification and analysis, searching for a DNA sequence and gene mapping. This section could usefully be expanded to provide a wider coverage of relevant methods. In summary, I am quite impressed with this package. I have found the text by Alberts et al to be useful in my teaching of advanced biochemistry courses and see the HyperCELL package as an effective tool to supple- ment learning in cell biology and related areas.

I have recently heard that the third edition of "Mol- ecular Biology of the Cell" is about to be released. I look forward to reading this new edition of the textbook.

R P Learmonth

Book Reviews

NMR of Proteins

Edited by G M Clore and A M Gronenborn. pp 338. Macmillan Press, Basingstoke. 1993. £65

ISBN 0-333-56662-9

In recent years NMR has been able to rival x-ray crystallography in providing high resolution protein structures. The editors and other contributors to this volume include many of the leading names in protein NMR that have made this possible. The methods used to determine protein structure are well presented; the NMR experiments themselves and the subsequent structural and molecular dynamics calculations. Protein folding and dynamics are also discussed. References are quite up-to-date (1992). Not all of the contributions are entirely original: two out of the nine chapters are 'adapted' from reviews that have appeared in prominent journals. Perhaps in keeping with the series title (Topics in Structural and Molecular Biology) although protein structure and dynamics are well covered, there is less on function: for example there is no mention of site-directed mutagensis. The book is not comprehensive and does not claim to be, but it is a useful package of certain aspects of protein NMR.

J Arnold

NMR of Paramagnetic Molecules

Edited by L J Berliner and J Reuben (volume 12 of the 'Biological Magnetic Resonance' series, pp 440. Plenum, New York. 1993. $95 ISBN 0-306-44387-2

It is 20 years since the last book to deal with this subject was published, and in the meantime a great deal has happened in NMR. Describing these advances as they relate to paramagnetic systems has been ably achieved in this book, which is the first of a two-volume set. All the contributors are very active in this area. Most of the chapters concern proteins, but one on water relaxation is of interest outside this area, with the advent of NMR imaging. The book is quite up-to-date, with references up to and including 1992. The use of multipulse NMR techniques in paramagnetic systems is clearly demonstrated, for lid and heteronuclei in both ID and 2D experiments. This is an impressive volume, and it really will be valuable to those working on such systems.

J Arnold

BIOCHEMICAL EDUCATION 22(2) 1994