- any of various proteins, as pepsin, originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action, as in digestion.
Origin of enzyme
1880–85; < Medieval Greek énzymos leavened (Greek en- en-2 + zȳ́m(ē) leaven + -os adj. suffix)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for enzyme
Women also make less of an enzyme called alcohol dehydrogenase, which breaks down alcohol before it hits the bloodstream.Elizabeth Peña and the Truth About Alcoholic Women
October 24, 2014
In particular, “prolonged fasting reduced the enzyme PKA,” explains the USC announcement.Fasting Might Regenerate Human Immune System
June 7, 2014
That life-giving source is the enzyme telomerase, which can actually lengthen telomeres.New Anti-Aging Pill Under Fire
April 11, 2011
It has nothing to do with aroma; the word refers to the enzyme aromatase.The Super Bowl May Harm Your Masculinity
Arthur De Vany
February 3, 2011
The answer lies in polyphenol oxidase, an enzyme that combines with oxygen to speed up cellular decomposition.Harvard Students Play With Food
December 28, 2010
If the products are removed, the action will continue, if the enzyme is not destroyed.
The enzyme must be specific for the protein since these differ in constitution.
By adding the enzyme maltase from yeast to a forty per cent.The Organism as a Whole
Here a similar action is caused by an enzyme called ptyalin.
This exchange appears to be aided by the presence of an enzyme in the lung tissues.
- any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalysts in specific biochemical reactions
C19: from Medieval Greek enzumos leavened, from Greek en- ² + zumē leaven
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for enzyme
Online Etymology Dictionary, © 2010 Douglas Harper
- Any of numerous proteins or conjugated proteins produced by living organisms and functioning as specialized catalysts for biochemical reactions.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- Any of numerous proteins produced in living cells that accelerate or catalyze the metabolic processes of an organism. Enzymes are usually very selective in the molecules that they act upon, called substrates, often reacting with only a single substrate. The substrate binds to the enzyme at a location called the active site just before the reaction catalyzed by the enzyme takes place. Enzymes can speed up chemical reactions by up to a millionfold, but only function within a narrow temperature and pH range, outside of which they can lose their structure and become denatured. Enzymes are involved in such processes as the breaking down of the large protein, starch, and fat molecules in food into smaller molecules during digestion, the joining together of nucleotides into strands of DNA, and the addition of a phosphate group to ADP to form ATP. The names of enzymes usually end in the suffix -ase.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.