enzyme n. (Physiol. Chem.) A protein produced by a living organism, capable of catalyzing a chemical reaction. Almost all processes in living organisms require some form of enzyme to cause the reactions to occur at a rate sufficient to support life. There are a very wide variety of enzymes, each specifically catalyzing a different chemical reaction, the sum of which cause the bulk of the physiological changes observed as life processes. Enzymes, like most proteins, are synthesized by the protein-synthetic mechanism of the living cell, at special sites on ribosomes, using the genetic information in messenger RNA transcribed from the genetic instructions stored as nuleotide sequences in the DNA (or in some viruses, the RNA) of the genome. Some examples of enzymes are: pepsin, diastase, rennet, DNA polymerase, invertase, glucose oxidase, protease, and ribonuclease. There are many other types of enzyme. Note: The 1913 Webster defined an enzyme as: An unorganized or unformed ferment, in distinction from an organized or living ferment; a soluble, or chemical, ferment.
... of rubber gloves from a rack, and pulled off some wilted stalks. From one of the healthy tanks, he took green leaves. He mashed the two kinds together on the edge of a bench and watched. "If it's chromazone, they've developed an enzyme by now that should eat the color out of ... — Let'em Breathe Space • Lester del Rey Read full book for free!
... of a somewhat complex nature. In the first place, it was not until the malt tax was repealed that the brewer was able to avail himself of the surplus diastatic energy present in malt, for the purpose of transforming starch (other than that in malted grain) into sugar. The diastatic enzyme or ferment (see below, under Mashing) of malted barley is present in that material in great excess, and a part of this surplus energy may be usefully employed in converting the starch of unmalted grain into sugar. The ... — Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 - "Brescia" to "Bulgaria" • Various Read full book for free!