Tuesday, July 27, 2010



There are two fundamental conditions for life. First, the organism must be able to self – replicate; second, it must be able to catalyze chemical reactions efficiently and selectively. Without catalysis, chemical reactions such as sucrose oxidation could not occur on a useful time scale, and thus could not sustain life. Enzymes, a reaction catalysts of biological system is the most remarkable and highly specialized proteins, which have extraordinary catalytic power, often far greater than that of synthetic or inorganic catalysts. They have a high degree of specificity for their substrates, they accelerate chemical reactions tremendously, and they function in aqueous solutions under very mild conditions of temperature and pH. Few non-biological catalysts have all these properties.
Enzymes are central to every biochemical process. Action in organized sequences, they catalyze the hundreds of stepwise reactions that degrade nutrient molecules, conserve and transform chemical energy, and make biological macromolecules from simple precursors. Most of the enzymes are proteins.
"Catalysis can be described formally in terms of a stabilization of the transition state through tight binding to the catalyst." -William P. Jencks, article in Advances in Enzymology, 1975

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