Getting A Handle On Chemical Kinetics

SHORT TAKES

DETERMINATION OF COMPLEX REACTION MECHANISMS: Analysis of Chemical, Biological, and Genetic Networks, by John Ross, Igor Schreiber, and Marcel O. Vlad, Oxford University Press, 2006, 226 pages, $94.50 (ISBN 978-0-19-517868-5)

Take a set of chemicals, possibly thousands of compounds, and mix them in a pot or even in a biological cell. What happens and how does it happen? These are the questions posed and discussed in the very nice book "Determination of Complex Reaction Mechanisms: Analysis of Chemical, Biological, and Genetic Networks," by John Ross of Stanford University; Igor Schreiber of Prague Institute of Chemical Technology, Czech Republic; Marcel O. Vlad of Stanford and the Center for Mathematical Studies, in Romania; and their colleagues.

Understanding reaction mechanisms is one of the central challenges in chemistry. We usually know the given set of reactants and what the products turn out to be, but what happens between point A and point B is often a mystery. For example, glycolysis is a complex biochemical reaction central to life with a net effect of converting glucose into two molecules of pyruvate. It occurs through an intricate sequence of steps involving a large number of intermediates for which a full description remains to be elucidated.

Without knowledge of a reaction mechanism, we have little ability to design synthetic strategies, understand the function of a chemical network, or potentially control the outcome of a complex reaction such as glycolysis. Determining the mechanism is indeed a daunting task, but it is one that the authors address in a systematic way.

No one method can be expected to provide enough information to elucidate the chemical mechanism of a complex reaction from experimental data. Thus, a battery of techniques can be used in a concerted attack. The authors discuss many of these methods, including the analysis of single-pulse perturbations, correlation metric construction, entropy metric correlation, genetic algorithms, stoichiometric network analysis, and lifetime analysis. They describe how specifically designed protocols in combination with statistical analysis can be used to obtain the needed information. The modern experimental techniques that can be used to provide the input concentration data also are reviewed in the book.

Chemical reactions often are carried out under far-from-equilibrium conditions, which is generally the case for many industrial reactions and almost all biological processes. In such circumstances, chemical concentrations may oscillate over time. One long chapter is devoted to how the mechanisms of oscillatory reactions can be determined.

The book is a synthesis of the extensive research the authors have carried out in this area over a number of years. Not only are the methods described in a very approachable way, but an attractive feature of the book is that the techniques are always illustrated by applications to model systems and experimental data. As a result, readers have a tool kit to use in the analysis of experiments to determine the mechanism from observations of chemical concentrations as a function of time.

For readers who want a fresh view of one of the central challenges in reaction kinetics, this is the book for you. There's no other book like it on the market. It should be useful to a wide audience in many fields including chemistry, biochemistry, biotechnology, engineering, and genomics.

Raymond Kapral is professor of chemistry at the University of Toronto.