The word “enzyme” is derived from the Modern Greek “enzumos,” which directly translates into “leavened.” Enzymes are generally biological molecules that living organisms produce in order to catalyze (which, in this case, to increase the speed or rates of) specific biochemical reactions. The substrates, which are what molecules are called at the beginning of the enzymatic reaction, will be converted into different molecules, known as products. Almost every chemical reaction that occurs in a biological cell will need enzymes in order to perform at a rate that is sufficient for sustaining life.
As with other biological catalysts, enzymes function through the process of lowering the activation energy for a reaction. This process will dramatically increase the rate of the enzymatic reaction and will allow the products (the result of enzymatic reactions) to form faster, and for reactions to achieve their equilibrium states in a shorter amount of time. With the use of enzymes as catalysts, the reactions are a million times faster than those reactions that do not utilize enzymes.
The activity of enzymes can be affected by other molecules. Inhibitors are known to be molecules that decrease the activity of enzymes, while activators are known as molecules that increase the activity of enzymes. Many kinds of drugs and poisons function as enzyme inhibitors. The activity of enzymes can also be affected by pressure, temperature, the chemical environment, and the concentration of a specific substrate.
There are enzymes that are used for commercial purposes, such as in the synthesis of various antibiotics. Some household products use enzymes in order to speed up several biochemical reactions—enzymes are known to be used in biological washing powders that are designed to break down protein and fat stains on clothes.
This category contains scientific information on enzymes, which are biological molecules that living organisms produce in order to catalyze (which, in this case, to increase the speed or rates of) specific biochemical reactions.
Andersen V., 1987: Erythrocyte cr1 c3b c4b receptor levels and disease activity in patients with sle. Scandinavian Journal Of Rheumatology: 339-346 Fifty-four patients with systemic lupus erythematosus (Sle) were examined for (1) Cr1 (C3b/C4b receptor) levels on erythrocytes by an enzyme-linked immunosorbent assay, (2) levels of circulating immune complexes (Ic) by a polyethylene glycol precipitation [...]
Pietzcker A., 1980: Erythrocyte catechol o methyl transferase activity in patients with affective disorders. Acta Psychiatrica Scandinavica: 427-437 Comt (catechol-o-l methyltransferase) enzyme characteristics (Km, V, ratio of meta/paramethylation) were determined in the red blood cells of 20 patients with endogenous depression, in 20 healthy controls matched as to age and sex, and in 10 patients [...]
Jackson E.Jr, 1982: Erythrocyte catechol o methyl transferase activity in pregnant women with pregnancy induced hypertension. American Journal Of Obstetrics & Gynecology: 177-178 Catechol-O-methyltransferase (Comt) is the enzyme that catalyzes the conversion of catechols, e.g., catecholamines and catechol estrogens, to their methyl ethers. Comt activity measured in erythrocytes (red blood cells) of healthy, pregnant women [...]
Eaton J.W., 1986: Erythrocyte catalase a somatic oxidant defense. Journal Of Clinical Investigation: 319-321 Mammalian erythrocytes have large amounts of catalase, an enzyme which catabolizes hydrogen peroxide (H2o2). Because catalase has a low affinity for H2o2, others have suggested that glutathione peroxidase clears most H2o2 within the erythrocyte and that catalase is of little import. [...]
Cook, L. R.; Angle, C. R.; Stohs, S. J., 1986: Erythrocyte arginase pyrimidine 5 nucleotidase and deoxypyrimidine 5 nucleotidase as indices of lead exposure. British Journal of Industrial Medicine 43(6): 387-390 The activities of three erythrocyte (rbc) enzymes, arginase, pyrimidine 5′-nucleotidase (P5n), and deoxypyrimidine 5′-nucleotidase (dP5N), were compared in 16 lead workers and 14 age [...]
More T., 1986: Erythrocyte arginase activity in goats water buffaloes and cattle. Indian Journal Of Animal Sciences: 32-33 An attempt was made to examine the red cell arginase activity in water-buffaloes, goats and cattle. Among all the species examined, only red cells of cattle showed active presence of the enzyme activity (1,276.+-. 117/.mu. mol. urea [...]
Davidson D.L.W., 1984: Erythrocyte anti oxidant enzymes in multiple sclerosis and the effect of hyperbaric oxygen. Neurochemical Research: 507-516 The activities of catalase, glutathione peroxidase and glutathione reductase, were not significantly different from normal whereas that of superoxide dismutase was decreased (P < 0.05) in erythrocytes from patients with multiple sclerosis Assay of the lipid [...]
Morck H.I., 1979: Erythrocyte and leukocyte enzymes in a case of paroxysmal nocturnal hemo globinuria. Scandinavian Journal Of Haematology: 253-257 In a patient with paroxysmal nocturnal hemoglobinuria (Pnh), enzymatic activities of erythrocytes and leukocytes were studied. Studies of autohemolysis were also performed. The following erythrocytary enzymes were measured: glucose-6-phosphate dehydrogenase (G-6-Pd), pyruvate kinase (Pk), glutathione [...]
Wang R., 1985: Erythrocyte aldehyde dehydrogenase and disulfiram like side effects of hypoglycemics and antianginals. Alcoholism Clinical & Experimental Research: 438-442 Disulfiram-like responses to various drug therapies are caused by elevated ethnol-derived blood acetaldehyde concentrations resulting from drug-induced inhibition of aldehyde dehydrogenase enzymes. We have found that the nitrate ester antianginal drugs, isosorbide dinitrate and [...]
Hockaday T.D.R., 1987: Erythrocyte aldehyde dehydrogenase plasma chlorpropamide concentrations and the chlorpropamide alcohol flush. Diabete & Metabolisme: 23-25 Erythrocyte aldehyde dehydrogenase activity (Ealdh) was measured in 21 diabetics on long-term chlorpropamide therapy. Median Ealdh was 0.362 units, range 0.108 to 0.750 units and correlated neither with previously assessed chlorpropamide alcohol flushing nor with coincident plasma [...]