Enzyme Catalysis
The term "catalysis" was introduced in 1835 by the Swedish scientist Jöns Jakob Berzelius (Altman & Cech, 1992). The catalysis phenomenon is very common in nature (most of the processes occurred in living organisms are catalytic), and is widely used in engineering (in the oil refining and petrochemical industry, in the production of sulfuric acid, ammonia, nitric acid, etc.) (Chuchill, 1866). Moreover, most of the industrial reactions are catalytic. Surprising (in the phenomenon of catalysis) is the fact that the catalysts, actively participating in the reaction, as a result, are not changed (Chuchill, 1866). In other words, the catalysts are not consumed in a chemical reaction. Since the catalyst is capable of multiplying participation in intermediate chemical interactions with reactants, it is often taken in a small amount, which is significantly less compared to the reactants (Chuchill, 1866). Conventional acids, bases, metal oxides and metals often perform as catalysts. However, there are also complex catalysts, search, and preparation of which, require a lot of labor (Chuchill, 1866). Since the catalysis is a common phenomenon, this paper will explore the definition of catalysis and catalyst, their parameters, as well as types of enzymes.
Catalysis is a selective acceleration of one of the possible thermodynamically allowed directions of the chemical reaction under the action of the catalyst (s), which repeatedly comes into the intermediate chemical interaction with its participants, and regains its chemical composition after each cycle of the intermediate chemical interactions (Chaplin, 2014). The catalyst, in turn, is a chemical that accelerates the reaction but not involved in the part of the reaction products (Chaplin, 2014). The main parameter of catalysis is that the catalyst changes the mechanism of reaction to energetically more favorable, i.e. lowers the activation energy (Chuchill, 1866). Along with a molecule of one of the reactant, the catalyst forms intermediate compound, in which the chemical bonds are weakened (Chaplin, 2014). This facilitates its reaction with the second reagent. Importantly, catalysts accelerate reversible reactions in both forward and reverse directions, so they do not displace the chemical equilibrium (Chaplin, 2014). Thus, all catalytic processes are spontaneous reactions i.e. flow in the direction of the decrease of the potential energy of the system. The catalyst does not shift the position of equilibrium of chemical reaction: near the equilibrium position, the same catalyst accelerates both forward and backward reactions equally.
The chemistry of catalysis studies substances, which change the rate of chemical reactions ("Chemical Reactions", n.d.). Substances, which inhibit the reaction, are known as inhibitors. Enzymes are biological catalysts, where the catalyst is not in stoichiometric ratios with products and is regenerated after each cycle of conversion of reactants to products ("Chemical Reactions", n.d.). Despite the emergence of new ways of activating molecules (plasma chemistry, radiation and laser effects, and other), catalysis is the basis of chemical production (relative proportion of catalytic processes is 80-90%) ("Chemical Reactions", n.d.). For example, in the reaction, which fed the whole mankind (solution to the problem of fixed nitrogen) by Haber-Bosch Cycle, …
