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ENZYME
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I. (noun)
Sense 1
Meaning:
Any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
Classified under:
Hypernyms ("enzyme" is a kind of...):
accelerator; catalyst ((chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected)
protein (any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes)
Meronyms (parts of "enzyme"):
active site (the part of an enzyme or antibody where the chemical reaction occurs)
Hyponyms (each of the following is a kind of "enzyme"):
oxidase (any of the enzymes that catalyze biological oxidation)
oxidoreductase (an enzyme that catalyzes oxidation-reduction)
papain (a proteolytic enzyme obtained from the unripe papaya; used as a meat tenderizer)
beta-lactamase; penicillinase (enzyme produced by certain bacteria that inactivates penicillin and results in resistance to that antibiotic)
pepsin (an enzyme produced in the stomach that splits proteins into peptones)
pepsinogen (precursor of pepsin; stored in the stomach walls and converted to pepsin by hydrochloric acid in the stomach)
phosphatase (any of a group of enzymes that act as a catalyst in the hydrolysis of organic phosphates)
fibrinolysin; plasmin (an enzyme that dissolves the fibrin of blood clots)
polymerase (an enzyme that catalyzes the formation of new DNA and RNA from an existing strand of DNA or RNA)
peptidase; protease; proteinase; proteolytic enzyme (any enzyme that catalyzes the splitting of proteins into smaller peptide fractions and amino acids by a process known as proteolysis)
reductase (an enzyme that catalyses the biochemical reduction of some specified substance)
chymosin; rennin (an enzyme that occurs in gastric juice; causes milk to coagulate)
secretase (a set of enzymes believed to snip pieces off a longer protein producing fragments of amyloid protein that bunch up and create amyloid protein plaques in brain tissue (the pathological hallmark of Alzheimer's))
streptodornase (an enzyme produced by some hemolytic strains of streptococcus that dissolves fibrinous secretions from infections; used medicinally (often in combination with streptokinase))
streptokinase (an enzyme produced by some strains of streptococcus that can liquefy blood clots by converting plasminogen to plasmin; used medicinally in some cases of myocardial infarction and pulmonary embolism)
SOD; superoxide dismutase (an enzyme that catalyzes the conversion of superoxide into hydrogen peroxide and oxygen)
telomerase (an enzyme in eukaryotic cells that can add telomeres to the ends of chromosomes after they divide)
transferase (any of various enzymes that move a chemical group from one compound to another compound)
trypsin (an enzyme of pancreatic origin; catalyzes the hydrolysis of proteins to smaller polypeptide units)
urease (an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia; is present in intestinal bacteria)
zymase (a complex of enzymes that cause glycolysis; originally found in yeast but also present in higher organisms)
ADA; adenosine deaminase (an enzyme found in mammals that can catalyze the deamination of adenosine into inosine and ammonia)
amylase (any of a group of proteins found in saliva and pancreatic juice and parts of plants; help convert starch to sugar)
cholinesterase (an enzyme that hydrolyses acetylcholine (into choline and acetic acid))
coagulase (an enzyme that induces coagulation)
collagenase (any enzyme that catalyzes the hydrolysis of collagen and gelatin)
complement (one of a series of enzymes in the blood serum that are part of the immune response)
catalase (enzyme found in most plant and animal cells that functions as an oxidative catalyst; decomposes hydrogen peroxide into oxygen and water)
Cox; cyclooxygenase (either of two related enzymes that control the production of prostaglandins and are blocked by aspirin)
decarboxylase (any of the enzymes that hydrolize the carboxyl group)
de-iodinase (an enzyme that removes the iodine radical)
disaccharidase (an enzyme that catalyzes the hydrolysis of disaccharides into monosaccharides)
elastase (a pancreatic enzyme that catalyzes the hydrolysis of elastin)
enterokinase (enzyme in the intestinal juice that converts inactive trypsinogen into active trypsin)
histaminase (enzyme that acts as a catalyst in converting histidine to histamine)
hyaluronidase; Hyazyme; spreading factor (an enzyme (trade name Hyazyme) that splits hyaluronic acid and so lowers its viscosity and increases the permeability of connective tissue and the absorption of fluids)
isomerase (an enzyme that catalyzes its substrate to an isomeric form)
kinase (an enzyme that catalyzes the conversion of a proenzyme to an active enzyme)
lipase (an enzyme secreted in the digestive tract that catalyzes the breakdown of fats into individual fatty acids that can be absorbed into the bloodstream)
lysozyme; muramidase (an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria)
MAO; monoamine oxidase (an enzyme that catalyzes the oxidation of many body compounds (e.g., epinephrine and norepinephrine and serotonin))
nitrogenase (an enzyme of nitrogen-fixing microorganisms that catalyzes the conversion of nitrogen to ammonia)
nuclease (general term for enzymes that catalyze the hydrolysis of nucleic acid by cleaving chains of nucleotides into smaller units)
Derivation:
enzymatic (of or relating to or produced by an enzyme)
Context examples:
The nuclear receptor CAR is activated by many different exogenous compounds, including acetaminophen, inducing expression of three cytochrome P450 enzymes that transform acetaminophen into NAPQI, a reactive and toxic metabolite.
(Acetaminophen Pathway, NCI Thesaurus/BIOCARTA)
Any substance that inhibits acetylcholinesterase (AchE), an enzyme that breaks down acetylcholine (Ach) in the synaptic cleft.
(Acetylcholinesterase Inhibitor, NCI Thesaurus)
Malate can be oxidized to pyruvate by the malic enzyme, with production of NADPH as well, that can contribute to fatty acid biosynthesis.
(Acetyl Group Shuttle Pathway, NCI Thesaurus/BIOCARTA)
This is done by interfering with the oxidation of iodide ion and iodotyrosyl groups through inhibition of the peroxidase enzyme.
(Methimazole, NLM, Medical Subject Headings)
Methotrexate binds to and inhibits the enzyme dihydrofolate reductase, resulting in inhibition of purine nucleotide and thymidylate synthesis and, subsequently, inhibition of DNA and RNA syntheses.
(Methotrexate, NCI Thesaurus)
After intratumoral injection, methotrexate binds to and inhibits the enzyme dihydrofolate reductase, resulting in inhibition of purine nucleotide and thymidylate synthesis and, subsequently, inhibition of DNA and RNA syntheses.
(Methotrexate-E Therapeutic Implant, NCI Thesaurus)
A representative example is the acinar cell located in the pancreas that produces pancreatic enzymes and juices.
(Acinar Cell, NCI Thesaurus)
A sequence in DNA that can be recognized by a specific methylase enzyme and that contains the specific base target for methyl transfer.
(Methylation Site, NCI Thesaurus)
When used in toothpaste, triclosan prevents the build-up of plaque bacteria by inhibiting the action of an enzyme known as enoyl reductase (ENR), which is involved in the production of fatty acids.
(Toothpaste ingredient may help fight drug-resistant malaria, University of Cambridge)
A condition in which normal metabolic processes are disrupted, usually because of a missing enzyme.
(Metabolic disorder, NCI Dictionary)
