Enzymes, biological catalysts
The catalytic properties and specificity of the biocatalysts are essential for the synthesis of a variety of compounds. Biological catalysts enzymesAre specialized proteins in the catalysis of biological reactions, are ranked among the essential biomolecules in cellular metabolism. Because of its specificity and catalytic power; enzymes are superior to chemical catalysts, so research around them grows progressively.
Definition of enzyme:
The name of enzyme (in yeast) was used from 1877, but several years earlier and suspected that some biological substances involved in fermentation sugar to form alcohol (hence the original name of yeast).
Brief historical review of enzyme catalysis:
The first general theory of enzymatic catalysis, was published by J. Berzelius in 1835 that included a model of the enzyme now known as diastase of malt, and noted that the hydrolysis of starch was more efficient when it was catalyzed by the enzyme, compared with the reaction hydrolyzed with sulfuric acid.
Years later, Louis Pasteur indicated that fermentation was catalyzed by enzymes, and postulated in 1860 that they were linked to the yeast cell structure, this was an important advance in the history of enzyme research.
Around 1897, E. Buchner was able to extract the enzymes that catalyze the alcoholic fermentation from the yeast cells. Subsequently obtained for the first time an enzyme crystallized as a result of the work of J. B. Summer in 1926, who isolated the enzyme urease extracted from the bean. During the period from 1930 to 1936, Northrop isolated pepsin, trypsin and chymotrypsin. This research confirmed the nature protein enzymes.
As a result of the changes in the world between 1940 and 1955 enzyme research progresses slowly, and until 1960 was released enzyme structural description and found the amino acid sequence of the enzyme ribonuclease. In 1965 he showed three-dimensional structure of lysozyme through X-ray crystallography, and proposed a catalytic mechanism in structural terms.
From the chemical synthesis of the enzyme ribonuclease, in 1969, development in the field has rapidly evolved enzymatic and currently have identified over 2000 different enzymes, of these about 200 have been crystallized.
On the other hand, the application of recombinant DNA techniques (deoxyribonucleic acid) to the study of enzymes, has been significant changes in the modification of catalytic activity and specificity through the integration of mutations in defined positions of the enzyme molecule.
Other biological catalysts:
The term biological catalyst, is not unique to the original enzymes, also applies to xenoenzimas, protein catalysts created in the laboratory and monoclonal antibodies with enzymatic activity, and an indication that both RNA (ribonucleic acid) as hemoglobin, have catalytic activities.
When comparing the rates of catalysis between a reaction catalyzed by an enzyme and a chemical catalyst, the first takes place more quickly and at lower temperatures. Because of its protean nature, the catalytic activity of enzymes depends on pH and reaction temperature. Another important feature of the enzyme activity is the specificity, the biocatalysts are specific to both the nature of the substrate used, as in the reaction they catalyze.