Two decades have passed since the mechanisms of protein synthesis became well enough understood to permit the genetic modification oforganisms. An impressive amount of new knowledge has emerged from the new technology, but much ofthe promise of20years ago has notyet been fulfilled. In biotechnology, efforts to increase the yields of commercially valuable metabolites have been less successful than ex pected, and when they have succeeded it has often been as much from selective breeding as from new methods. The cell is more complicated than what is presented in the classical teaching of biochemistry, it contains more structure than was dreamed of 20 years ago, and the behaviour ofany systemofenzymes is more elaborate than can be explained in terms ofa single supposedly rate-limiting enzyme. Even if classical enzymology and meta bolism may have seemed rather unfashionable during the rise ofmolecular biology, they remain central to any modification ofthe metabolic behaviour oforganisms. As such modification is essential in much ofbiotechnology and drug development, bio technologists can only ignore these topics at their peril."

THIS BOOK collects together papers given at a NATO Advanced Research Workshop held at Il Ciocco (Lucca), Italy, from the 9th to the 15th April, 1989. It sets out to present the current state of understanding of the principles governing the way fluxes and concentrations are maintained and controlled in metabolic systems. Although this is a topic that has held the interest of biochemists for many years, it is only quite recently that the methods of analysing the kinetics of multi-enzyme pathways developed over the past two decades have come to be widely discussed or applied experimentally. Many biochemists remain sceptical that the new methods offer a real advance (except in complexity) over the landmark discoveries of the 1950s and 1960s relating to inhibition of enzymes at branch-points by the end products of metabolic pathways, and the interpretation of allosteric effects and cooperativity. Even those who have become convinced that the classical ideas provide only the starting point for understanding metabolic control have been by no means unanimous in their assess ment of the direction in which one should advance. In this book we have tried to include all of the current points of view, including the view that the classical theories tell us all that we need to know. We have not seen it as our role as editors to paper over the cracks that exist and to pretend that we can speak to the world with one voice."

THIS BOOK collects together papers given at a NATO Advanced Research Workshop held at Il Ciocco (Lucca), Italy, from the 9th to the 15th April, 1989. It sets out to present the current state of understanding of the principles governing the way fluxes and concentrations are maintained and controlled in metabolic systems. Although this is a topic that has held the interest of biochemists for many years, it is only quite recently that the methods of analysing the kinetics of multi-enzyme pathways developed over the past two decades have come to be widely discussed or applied experimentally. Many biochemists remain sceptical that the new methods offer a real advance (except in complexity) over the landmark discoveries of the 1950s and 1960s relating to inhibition of enzymes at branch-points by the end products of metabolic pathways, and the interpretation of allosteric effects and cooperativity. Even those who have become convinced that the classical ideas provide only the starting point for understanding metabolic control have been by no means unanimous in their assess ment of the direction in which one should advance. In this book we have tried to include all of the current points of view, including the view that the classical theories tell us all that we need to know. We have not seen it as our role as editors to paper over the cracks that exist and to pretend that we can speak to the world with one voice."

Two decades have passed since the mechanisms of protein synthesis became well enough understood to permit the genetic modification oforganisms. An impressive amount of new knowledge has emerged from the new technology, but much ofthe promise of20years ago has notyet been fulfilled. In biotechnology, efforts to increase the yields of commercially valuable metabolites have been less successful than ex pected, and when they have succeeded it has often been as much from selective breeding as from new methods. The cell is more complicated than what is presented in the classical teaching of biochemistry, it contains more structure than was dreamed of 20 years ago, and the behaviour ofany systemofenzymes is more elaborate than can be explained in terms ofa single supposedly rate-limiting enzyme. Even if classical enzymology and meta bolism may have seemed rather unfashionable during the rise ofmolecular biology, they remain central to any modification ofthe metabolic behaviour oforganisms. As such modification is essential in much ofbiotechnology and drug development, bio technologists can only ignore these topics at their peril."