The Importance Of Enzymes

Enzymes: Enzymes are the biological catalysts which are globular proteins in nature. They catalyze or accelerate the chemical reactions. They speed up the chemical reactions by providing an alternative reaction pathway of lower activation energy. The molecules on which enzymes acts are called substrates and these are converted into different molecules called products. All the metabolic processes in the cell need enzymes to occur at a faster rate to sustain life. Like all other catalysts, enzymes take part in the chemical reactions - that is how they provide an alternative reaction pathway. But enzymes do not undergo permanent changes and so remain unchanged at the end of the reaction. They can only alter the rate of reaction, not the position

They are not usually very selective. In contrast enzymes are usually very highly selective and they catalyze specific reactions only. This specificity is due to the different shapes of the enzyme molecules. Enzymes' specificity is mainly due to their unique three-dimensional structures. Like all other catalysts, enzymes also increase the rate of reaction by lowering the activation energy of the reaction. Some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5'-phosphate decarboxylase, which allows a reaction that would otherwise take 78 million years to occur in milliseconds. Enzymes are usually much larger than their substrates. Sizes range from just 62 amino acid residues, for the monomer of 4-oxalocrotonate tautomerase, to over 2,500 residues in the animal fatty acid synthase. Only small portion of their structure (2-4 amino acids) is involved in catalytic activity. The remaining of the enzyme structure serves to maintain the precise orientation and dynamics of the enzyme

Pectins contribute to the viscosity and turbidity of fruit juice. We can use the mixture of pectinases and amylases to clarify fruit juices. It can decrease the filtration time up to 50%. The fruit juice volume of banana,grapes and apples show an increase when the fruit pulps are treated with pectinases. Combination of Pectinases with other enzymes, viz., cellulases, arabinases and xylanases, is used to increase the pressing efficiency for the extraction of fruit juices. The peels of citrus fruit can be soften for removal by vacuum infusion of pectinases. In future this technique can be used to replace hand cutting for the production of canned segments. Infusion of free stone peaches with pectinmethylesterase and calcium results in four times firmer fruits. This technique can be applied to pickle processing where excessive softening may occur in