Enzymes


An enzyme is a type of protein that accelerates, or catalyzes, a chemical reaction. They are essential to life, since all work accomplished in any cell is done by enzymes.

Enzymes: Catalyzing Agents

Biological life and cellular activity is dependent upon enzymes. Without them, chemical reactions in biological cells would be too slow or result in different chemical products. Enzymatic reactions allow cells to construct and take apart things in order to accomplish growth and reproduction. Any mutation, overproduction, underproduction or absence of single enzyme can lead to severe disease states, including mental retardation. Like other proteins, their function is determined by their structure. They are used in industry with a wide range of applications including baking, brewing, rubber, and paper production, and are used in products like detergents, baby foods, dairy, fruit juices, and sweeteners.

Enzyme Specificity and Structure

Enzymatic reactions typically occur within a narrow temperature range, 30-40 degrees Celsius. Adding to their further complexity, each enzyme has an optimal pH range for activity, and function depends on maintenance of the three dimensional structure of the molecule. These complex molecule structures fit together and react in very precise manners, yet may modify themselves in accommodating the interaction with a substrate. Enzymes may have very specific job functions, such as maltase's ability to break maltose molecules, which can do very quickly, but serves no other purpose. Other enzymes may bond atoms and molecules. More than 1,500 different types of enzymes have been identified.

Enzymes are built by amino acids, and are thereby considered proteins. An enzyme may be comprised with 100 to 1,000 amino acids laid out in a specific and unique order, compacted into a distinctive 3 dimensional shape. This shape allows the enzyme to perform a specific act in the course of a chemical reaction.

In 1860 Louis Pasteur Realized that enzymes were required for successful fermentation but assumed they were contained within the structure of a yeast cell. In 1897 a German chemist, Edward Buchner, showed that enzymes could react to ferment sugars to alcohol and carbon dioxide outside of a cellular environment.

Enzyme Deficiency

Deficiencies or malfunctions of enzymes are known to cause a variety of metabolic disorders. Albinism is a disorder where a person lacks the enzyme tyrosinase, which is needed for skin, hair, and eye pigmentation. The lack of other enzymes might lead to mental retardation or food intolerances. Food additives and supplements are available for people who are suspected of lacking certain digestive enzymes. Digestive enzymes are secreted by the salivary glands, stomach glands, pancreas, and by glands in the small intestine. Any deficiency or mutation can cause digestive, carbohydrate, protein, and lipid metabolism disorders.

By Doug Vanisky           


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