A protein that regulates the rate of a chemical reaction in the body. There are thousands of enzymes, each with a different chemical structure. It is this structure that determines the specific reaction regulated by an enzyme. Different enzymes occur in different tissues, reflecting their specialized functions. In order to function properly, many enzymes need an additional component, known as a coenzyme, which is often derived from a vitamin or mineral. Enzyme activity is influenced by many factors, and can be increased or inhibited by certain drugs.Measuring enzyme levels in the blood can be useful in diagnosing certain disorders. For example, the level of heart muscle enzymes is raised following a myocardial infarction because the damaged heart muscle releases enzymes into the bloodstream. Many different inherited metabolic disorders, including phenylketonuria, galactosaemia, and G6PD deficiency, are caused by defects in, or deficiencies of, specific enzymes.
Enzymes can play a valuable role in treating certain disorders. Pancreatic enzymes may be given as digestive aids to people who have malabsorption related to pancreatic disease. Enzymes such as streptokinase and tissue-plasminogen activator are used to treat acute thrombosis and embolism.
A protein that acts as a catalyst for the body’s metabolic processes. The body contains thousands of enzymes, with each cell producing several varieties. The ?rst enzyme was obtained in a reasonably pure state in 1926. Since then, several hundred enzymes have been obtained in pure crystalline form. They are present in the digestive ?uids and in many of the tissues, and are capable of producing in small amounts the transformation on a large scale of various compounds. Examples of enzymes are found in the PTYALIN of saliva and DIASTASE of pancreatic juice which split up starch into sugar; the PEPSIN of the gastric juice and the trypsin of pancreatic juice which break proteins into simpler molecules and eventually into the constituent amino acids; and the thrombin of the blood which causes coagulation.
The diagnosis of certain disorders can be helped by measuring the concentrations of various enzymes in the blood. After a heart attack (myocardial infarction – see HEART, DISEASES OF), raised levels of heart enzymes occur as a result of damage to the cells of the heart muscle. Some inherited diseases such as GALACTOSAEMIA and PHENYLKETONURIA are the result of de?ciencies of certain enzymes.
Enzymes can be a useful part of treatment for some disorders. STREPTOKINASE, for example, is used to treat THROMBOSIS; wound-dressings containing papain from the pawpaw fruit – this contains protein-digesting enzymes – assist in the healing process; and pancreatic enzymes can be of value to patients with malabsorption caused by disorders of the PANCREAS.
Usually a protein made by the body to make chemical reactions take place at a faster rate or to cause a colour change in a laboratory test.
n. a protein that, in small amounts, speeds up the rate of a biological reaction without itself being used up in the reaction (i.e. it acts as a catalyst). An enzyme acts by binding with the substance involved in the reaction (the substrate) and converting it into another substance (the product of the reaction). An enzyme is relatively specific in the type of reaction it catalyses; hence there are many different enzymes for the various biochemical reactions. Each enzyme requires certain conditions for optimum activity, particularly correct temperature and pH, the presence of *coenzymes, and the absence of specific inhibitors. Enzymes are unstable and are easily inactivated by heat or certain chemicals. They are produced within living cells and may act either within the cell (as in cellular respiration) or outside it (as in digestion). The names of enzymes usually end in ‘-ase’; enzymes are named according to the substrate upon which they act (as in lactase), or the type of reaction they catalyse (as in hydrolase).
Enzymes are essential for the normal functioning and development of the body. Failure in the production or activity of a single enzyme may result in metabolic disorders; such disorders are often inherited and some have serious effects. —enzymatic adj.
complex proteins that are produced by living cells, and catalyse specific biochemical reactions.
An enzyme is a substance produced in the body, acting as a catalyst to trigger chemical change in another. Complex substances are thereby broken down into simple compounds to facilitate assimilation and absorption, as in the digestive juices. ... enzymes
(PERT) a therapeutic approach using supplements of the digestive enzymes lipase, amylase, and protease (Creon, Pancrex), which are given when there is insufficient endogenous production of pancreatic enzymes: for example, to patients with pancreatic cancer or cystic fibrosis. The capsules must be taken with all meals and snacks to be effective. PERT treats the symptoms of *steatorrhoea.... pancreatic enzyme replacement therapy
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