Chapter 14 - General Kinetic Regularities in Homogeneous Catalysis

Abstract

Homogeneous catalysts and enzymes accelerate processes with rather complicated kinetics. As a rule, several substrates are involved in reactions, multistage chemical transformations, and electron transfer inside enzymes is often observed, and the cooperative interaction of active sites, positive and negative feedback, and so on are met. This chapter considers some problems of the formal kinetics of homogeneous catalytic and enzymatic reactions. Since many public editions are devoted to the kinetics of chemical and enzymatic reactions, this chapter revises briefly only general problems. A great attention is given to sections directly associated with the specific problems of catalysis. It is believed that a chemical catalytic process, as well as an enzymatic reaction comprises a certain sequence of elementary chemical steps. Each of these steps proceeds by “ordinary” laws of chemical kinetics. The accelerating action of a catalyst is accounted for by the fact that its active centers become involved in such chemical reactions with substrate molecules and with such rates, which lead to an increase in the velocity of the process as a whole. Within the framework of these concepts, enzymes are characterized by a set of certain specific properties, which have been “polished off” in the course of a biological evolution.