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.
Dey, Runu; Datta, Salil C., 1994: Leishmanial glycosomes contain superoxide dismutase. Biochemical Journal. 301(2): 317-319 In this work we report that superoxide dismutase is entrapped in a microbody-like organelle, the glycosome, present in Leishmania spp. Studies on the sensitivity of the enzyme to various inhibitors indicated that glycosomal superoxide dismutase is predominantly of the Cu/Zu [...]
He, Z. H.; Li, J. M.; Sundqvist, C.; Timko, M. P., 1994: Leaf developmental age controls expression of genes encoding enzymes of chlorophyll and heme biosynthesis in pea (Pisum sativum L.). Plant Physiology 106(2): 537-546 The effects of leaf developmental age on the expression of three nuclear gene families in pea (Pisum sativum L.) coding [...]
Cancilla, M. R.; Hillier, A. J.; Davidson, B. E., 1995: Lactococcus lactis glyceraldehyde-3-phosphate dehydrogenase gene, gap: further evidence for strongly biased codon usage in glycolytic pathway genes. Microbiology Reading 141(4): 1027-1036 The gene gap, encoding glyceraldehyde-3-phosphate dehydrogenase (Ec 220.127.116.11), was isolated from a genomic library of Lactococcus lactis Lm0230 Dna. Plasmids containing the L. lactis [...]
Jeune, C. le; Lonvaud Funel, A., 1994: Lactobacillus hilgardii and Lactobacillus brevis DNA analysis by restriction fragment length polymorphism (RFLP). Food Microbiology 11(3): 195-202 Fifteen heterofermentative lactobacilli belonging to the Lactobacillus hilgardii and Lactobacillus brevis species were studied. In a Dna/Dna hybridization test most of them give the expected answer since their Dna hybridized with [...]
Maga, Giovanni; Verri, Annalisa; Bonizzi, Luigi; Ponti, Wilma; Poli, Giorgio; Garbesi, Anna; Niccolai, Daniela; Spadari, Silvio; Focher, Federico, 1993: Lack of stereospecificity of suid pseudorabies virus thymidine kinase. Biochemical Journal. 294(2): 381-385 We have partially purified suid pseudorabies virus (Prv) thymidine kinase from infected thymidine kinase- mouse cells, and cytosolic swine thymidine kinase from lymphatic [...]
Passerat, Brigitte; Desmaison, Anne Marie, 1995: Lactase activity of Bifidobacterium bifidum. Nutrition Research. 15(9): 1287-1295 Lactose hydrolase is a small intestinal enzyme which hydrolyzes the carbohydrate lactose from dairy products. During the neonatal period, the enzyme is essential in human nutrition. Later, the specific activity of lactase decreases to low adult levels. In many adult [...]
Hu, Guizhou; Han, Chi; Wild, Christopher P.; Hall, Janet; Chen, Junshi, 1992: Lack of effects of selenium on N-nitrosomethylbenzylamine-induced tumorigenesis, DNA methylation, and oncogene expression in rats and mice. Nutrition & Cancer. 18(3): 287-295 The effects of dietary selenium deficiency and excess on N-nitrosomethylbenzylamine-(Nmba) induced esophageal neoplasia in rats and forestomach tumors in mice and [...]
Rhoads, J. Marc; Chen, Wunian; Chu, Peter; Berschneider, Helen M.; Argenzio, Robert A.; Paradiso, Anthony M., 1994: L-Glutamine and L-asparagine stimulate Na+-H+ exchange in porcine jejunal enterocytes. American Journal Of Physiology. 266(5 Part 1): G828-G838 L- Glutamine (Gln) is a major respiratory fuel and substrate for nucleic acid synthesis in mammalian intestinal cells. The structurally [...]
Dehaye, L.; Alban, C.; Job, C.; Douce, R.; Job, D., 1994: Kinetics of the two forms of acetyl-CoA carboxylase from Pisum sativum. Correlation of the substrate specificity of the enzymes and sensitivity towards aryloxyphenoxypropionate herbicides. European Journal of Biochemistry 225(3): 1113-1123 Steady-state kinetics of the 220-kDa form of acetyl-CoA carboxylase (Acc220), as; purified from mature [...]
Picon, A.; Gaya, P.; Medina, M.; Nunez, M., 1995: Kinetics of milk coagulation by mixtures of cyprosin and chymosin. Milchwissenschaft. 50(7): 393-395 The kinetics of milk coagulation by the proteolytic enzymes cyprosin and chymosin, present in vegetable and animal rennet, as single coagulants and in mixtures were monitored by thrombelastography. Clotting time for milk coagulation [...]