enzyme

en·zyme

noun \ˈen-ˌzīm\

Definition of ENZYME

: any of numerous complex proteins that are produced by living cells and catalyze specific biochemical reactions at body temperatures

Origin of ENZYME

German Enzym, from Middle Greek enzymos leavened, from Greek en- + zymē leaven — more at juice

First Known Use: 1881

Other Biochemistry Terms

bile, biodegradable, capsaicin, keratin, metabolism

Rhymes with ENZYME

airtime, all-time, bedtime, begrime, big time, big-time, birdlime, buy time, call time, crunch time, cut time, daytime, downtime, dreamtime, drive time, eye rhyme, face time, flextime, foretime, free-climb, full-time, half dime, halftime, hang time, hate crime, hill climb, in time, key lime, lifetime, longtime, lunchtime, make time, Mannheim, mark time, Maytime, mealtime, meantime, Mülheim, nighttime, noontime, old-time, onetime, on time, part-time, pastime, peacetime, Pforzheim, playtime, post time, prime time, quicklime, quick time, ragtime, real time, rock climb, schooltime, seedtime, showtime, sight rhyme, small-time, sometime, Sondheim, space-time, springtime, sublime, teatime, two-time, uptime, Waldheim, war crime, wartime, wind chime

en·zyme

noun \ˈen-ˌzīm\   (Medical Dictionary)

Medical Definition of ENZYME

: any of numerous complex proteins that are produced by living cells and catalyze specific biochemical reactions at body temperatures

enzyme

noun    (Concise Encyclopedia)

Substance that acts as a catalyst in living organisms, regulating the rate at which life's chemical reactions proceed without being altered in the process. Enzymes reduce the activation energy needed to start these reactions; without them, most such reactions would not take place at a useful rate. Because enzymes are not consumed, only tiny amounts of them are needed. Enzymes catalyze all aspects of cell metabolism, including the digestion of food, in which large nutrient molecules (including proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy; and the construction of cellular materials and components. Almost all enzymes are proteins; many depend on a nonprotein cofactor, either a loosely associated organic compound (e.g., a vitamin; see coenzyme) or a tightly bound metal ion (e.g., iron, zinc) or organic (often metal-containing) group. The enzyme-cofactor combination provides an active configuration, usually including an active site into which the substance (substrate) involved in the reaction can fit. Many enzymes are specific to one substrate. If a competing molecule blocks the active site or changes its shape, the enzyme's activity is inhibited. If the enzyme's configuration is destroyed (see denaturation), its activity is lost. Enzymes are classified by the type of reaction they catalyze: (1) oxidation-reduction, (2) transfer of a chemical group, (3) hydrolysis, (4) removal or addition of a chemical group, (5) isomerization (see isomer; isomerism), and (6) binding together of substrate units (polymerization). Most enzyme names end in -ase. Enzymes are chiral catalysts, producing mostly or only one of the possible stereoisomeric products (see optical activity). The fermentation of wine, leavening of bread, curdling of milk into cheese, and brewing of beer are all enzymatic reactions. The uses of enzymes in medicine include killing disease-causing microorganisms, promoting wound healing, and diagnosing certain diseases.