| slovo | definícia |
enzyme
(encz) | enzyme,enzym n: Zdeněk Brož |
enzyme
(gcide) | enzyme \en"zyme\ ([e^]n"z[imac]m), n. [Pref. en- (Gr. 'en in) +
Gr. zy`mh leaven.] (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.
[1913 Webster +PJC]
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.
[PJC] |
enzyme
(wn) | enzyme
n 1: any of several complex proteins that are produced by cells
and act as catalysts in specific biochemical reactions |
| | podobné slovo | definícia |
coenzyme
(encz) | coenzyme,koenzym n: Zdeněk Brož |
coenzyme a
(encz) | coenzyme A, n: |
coenzyme q
(encz) | coenzyme Q, n: |
enzyme-linked-immunosorbent serologic assay
(encz) | enzyme-linked-immunosorbent serologic assay, n: |
enzymes
(encz) | enzymes,enzymy n: pl. Zdeněk Brož |
proenzyme
(encz) | proenzyme, n: |
proteolytic enzyme
(encz) | proteolytic enzyme, n: |
restriction enzyme
(encz) | restriction enzyme, n: |
abomasal enzyme
(gcide) | Rennin \Ren"nin\ (r[e^]n"n[i^]n), n. (Biochem.)
A milk-clotting enzyme obtained from the true stomach
(abomasum) of a suckling calf. Mol. wt. about 31,000. Also
called chymosin, rennase, and abomasal enzyme. --[Merck
Man. 11]
[1913 Webster] |
coenzyme
(gcide) | coenzyme \co*en"zyme\ (k[-o]*[e^]n"z[imac]m), (Biochem.)
a molecule that is essential for the activity of some
enzymes; it may exist free in solution within a living
organism, but functions by binding to an enzyme to assist in
catalyzing a reaction. The molecule itself may be temporarily
changed during the reaction, but is ultimately restored to
its original form. Many vitamins function as coenzymes.
[PJC] |
coenzyme A
(gcide) | coenzyme A \co*en"zyme A`\ (k[-o]*[e^]n"z[imac]m [=a]`),
(Biochem.)
a coenzyme (C21H36N7O16P3S) that participates in the
transfer of acetyl groups in biochemical reactions; --
abbreviated CoA. It contains adenosine, phosphate,
pantothenic acid and cysteamine groups. The acetyl group to
be transferred during biosynthesis is temporarily attached to
the free sulhydryl of the cysteamine group to form a
thioester, in which state it is called acetyl coenzyme A. The
strength of a preparation of coenzyme A may be expressed by
the Lippman unit; one milligram of CoA contains 413 Lippman
units.
[PJC] |
coenzyme R
(gcide) | biotin \bi"o*tin\ n.
a B vitamin (C10H16N2O3S) that aids in body growth; --
called also vitamin H and coenzyme R. It functions as a
coenzyme in many carboxylation reactions.
Note: Biotin binds tightly to the substance avidin, found in
raw egg-whites. Rats or chick on a diet high in raw
egg-white may develop skin lesions and retarded growth,
which can be prevented by adding biotin to the diet.
--[MI11]
Syn: .
[WordNet 1.5 +PJC] |
enzymes
(gcide) | Ferment \Fer"ment\, n. [L. fermentum ferment (in senses 1 & 2),
perh. for fervimentum, fr. fervere to be boiling hot, boil,
ferment: cf. F. ferment. Cf. 1st Barm, Fervent.]
1. That which causes fermentation, as yeast, barm, or
fermenting beer.
[1913 Webster]
Note: Ferments are of two kinds: (a) Formed or organized
ferments. (b) Unorganized or structureless ferments.
The latter are now called enzymes and were formerly
called soluble ferments or chemical ferments.
Ferments of the first class are as a rule simple
microscopic vegetable organisms, and the fermentations
which they engender are due to their growth and
development; as, the acetic ferment, the {butyric
ferment}, etc. See Fermentation. Ferments of the
second class, on the other hand, are chemical
substances; as a rule they are proteins soluble in
glycerin and precipitated by alcohol. In action they
are catalytic and, mainly, hydrolytic. Good examples
are pepsin of the dastric juice, ptyalin of the salvia,
and disease of malt. Before 1960 the term "ferment" to
mean "enzyme" fell out of use. Enzymes are now known to
be globular proteins, capable of catalyzing a wide
variety of chemical reactions, not merely hydrolytic.
The full set of enzymes causing production of ethyl
alcohol from sugar has been identified and individually
purified and studied. See enzyme.
[1913 Webster +PJC]
2. Intestine motion; heat; tumult; agitation.
[1913 Webster]
Subdue and cool the ferment of desire. --Rogers.
[1913 Webster]
the nation is in a ferment. --Walpole.
[1913 Webster]
3. A gentle internal motion of the constituent parts of a
fluid; fermentation. [R.]
[1913 Webster]
Down to the lowest lees the ferment ran. --Thomson.
[1913 Webster]
ferment oils, volatile oils produced by the fermentation of
plants, and not originally contained in them. These were
the quintessences of the alchemists. --Ure.
[1913 Webster] |
hydrolytic enzyme
(gcide) | Hydrolytic \Hy`dro*lyt"ic\, a. [Hydro-, 1 + Gr. ? to loose.]
1. (Chem.) Tending to remove or separate water; eliminating
water. [archaic]
[1913 Webster]
2. (Chem.) of, pertaining to, or accompanied by hydrolysis.
[PJC]
Hydrolytic agents, such as sulphuric acid or caustic
alkali. --Encyc. Brit.
[1913 Webster]
Hydrolytic ferment (Physiol. Chem.), an enzyme (formerly
referred to as a ferment), which acts only in the presence
of water, and which causes the substance acted upon to
take up a molecule of water, resulting in the splitting of
a chemical bond and often splitting one compound into two.
Thus, diastase of malt, ptyalin of saliva, and boiling
dilute sulphuric acid all convert starch by hydration into
dextrin and sugar. Nearly all of the digestive enzymes are
hydrolytic in their action. Since 1910 such an enzyme is
usually referred to as a {hydrolase} or {{hydrolytic
enzyme}}.
[1913 Webster +PJC] |
proenzyme
(gcide) | proenzyme \pro"en*zyme\, n. [.] (Bioch.)
Any one of a class of proteins that are converted, in the
normal course of cellular metabolism, into one or more active
enzymes; also called zymogen. The conversion usually is due
to a specific cleavage of a peptide bond by another enzyme,
or may be due to acid.
[PJC] |
5-hydroxy-3-methylglutaryl-coenzyme a reductase
(wn) | 5-hydroxy-3-methylglutaryl-coenzyme A reductase
n 1: a liver enzyme that is responsible for producing
cholesterol [syn: HMG-CoA reductase,
5-hydroxy-3-methylglutaryl-coenzyme A reductase] |
angiotensin converting enzyme
(wn) | angiotensin converting enzyme
n 1: proteolytic enzyme that converts angiotensin I into
angiotensin II [syn: angiotensin converting enzyme,
angiotensin-converting enzyme, ACE] |
angiotensin-converting enzyme
(wn) | angiotensin-converting enzyme
n 1: proteolytic enzyme that converts angiotensin I into
angiotensin II [syn: angiotensin converting enzyme,
angiotensin-converting enzyme, ACE] |
angiotensin-converting enzyme inhibitor
(wn) | angiotensin-converting enzyme inhibitor
n 1: an antihypertensive drug that blocks the formation of
angiotensin II in the kidney, leading to relaxation of the
arteries; promotes the excretion of salt and water by
inhibiting the activity of the angiotensin converting
enzyme; also used to treat congestive heart failure [syn:
ACE inhibitor, angiotensin-converting enzyme inhibitor] |
apoenzyme
(wn) | apoenzyme
n 1: a protein that combines with a coenzyme to form an active
enzyme |
coenzyme
(wn) | coenzyme
n 1: a small molecule (not a protein but sometimes a vitamin)
essential for the activity of some enzymes |
coenzyme a
(wn) | coenzyme A
n 1: a coenzyme present in all living cells; essential to
metabolism of carbohydrates and fats and some amino acids |
coenzyme q
(wn) | coenzyme Q
n 1: any of several quinones found in living cells and that
function as coenzymes that transfer electrons from one
molecule to another in cell respiration [syn: ubiquinone,
coenzyme Q] |
enzyme-linked-immunosorbent serologic assay
(wn) | enzyme-linked-immunosorbent serologic assay
n 1: an assay that relies on an enzymatic conversion reaction
and is used to detect the presence of specific substances
(such as enzymes or viruses or antibodies or bacteria)
[syn: enzyme-linked-immunosorbent serologic assay,
ELISA] |
proenzyme
(wn) | proenzyme
n 1: any of a group of compounds that are inactive precursors of
enzymes and require some change (such as the hydrolysis of
a fragment that masks an active enzyme) to become active
[syn: proenzyme, zymogen] |
proteolytic enzyme
(wn) | proteolytic enzyme
n 1: any enzyme that catalyzes the splitting of proteins into
smaller peptide fractions and amino acids by a process
known as proteolysis [syn: protease, peptidase,
proteinase, proteolytic enzyme] |
restriction enzyme
(wn) | restriction enzyme
n 1: any of the enzymes that cut nucleic acid at specific
restriction sites and produce restriction fragments;
obtained from bacteria (where they cripple viral invaders);
used in recombinant DNA technology [syn: {restriction
endonuclease}, restriction nuclease, {restriction
enzyme}] |
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