Enzyme that breaks down the milk sugar lactose into glucose and galactose. Persons with a deficiency of lactase in the gut can develop abdominal cramping and diarrhea after ingesting milk products.
* * *
SYN: β-d-galactosidase.

* * *

lac·tase 'lak-.tās, -.tāz n an enzyme that hydrolyzes esp. lactose to glucose and galactose and occurs esp. in the intestines of young mammals and in yeasts

* * *

an enzyme, secreted by the glands of the small intestine, that converts lactose (milk sugar) into glucose and galactose during digestion.

* * *

lac·tase (lakґtās) a β-galactosidase [EC] occurring in the brush border membrane of the intestinal mucosa; together with glycosylceramidase (phlorizin hydrolase), it forms the β-glycosidase complex (q.v.). The enzyme catalyzes the hydrolytic cleavage of lactose to galactose and glucose and also cleaves terminal nonreducing galactose residues from β-glycosides with large hydrophilic aglycons. Reduced or absent enzyme activity (lactase deficiency) may result in symptoms of lactose intolerance. [USP] an official preparation of lactase, derived from the mold Aspergillus oryzae.

Medical dictionary. 2011.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Lactase — Masse/Länge Primärstruktur 1927 Aminosäuren; 219 kDa …   Deutsch Wikipedia

  • lactase — [ laktaz ] n. f. • v. 1900; de lact(o) et ase ♦ Biochim. Enzyme qui transforme le lactose en glucose et galactose. ⇒ galactosidase. ● lactase nom féminin Enzyme sécrétée par la muqueuse intestinale, permettant l assimilation du lactose. lactase n …   Encyclopédie Universelle

  • lactase — |lâct| s. f. Diástase que converte a lactose em glicose e galactose …   Dicionário da Língua Portuguesa

  • lactase — [lak′tās΄] n. [ LACT(O) + (DIAST)ASE] an enzyme, present in certain yeasts and in the intestines of animals, which splits lactose into glucose and galactose …   English World dictionary

  • Lactase — La lactase () est une enzyme présente essentiellement chez les mammifères. Sa fonction principale est de permettre la dissociation du lactose, ce qui autorise la digestion du lait. La lactase a pour nom scientifique complet lactase phlorizine… …   Wikipédia en Français

  • Lactase — Protein Name=Lactase Symbol=LCT AltSymbols=LAC; LPH; LPH1 HGNCid=6530 Chromosome=2 Arm=q Band=21 LocusSupplementaryData= ECnumber= OMIM=603202 EntrezGene=3938 RefSeq=NM 002299 UniProt=P09848 Lactase (LCT), a part of the β galactosidase… …   Wikipedia

  • lactase — /lak tays, tayz /, n. Biochem. an enzyme capable of hydrolyzing lactose into glucose and galactose. [1890 95; LACT + ASE] * * * ▪ enzyme       any of a group of enzymes found in the small intestine, liver, and kidney of mammals that catalyze the… …   Universalium

  • lactase — laktazė statusas T sritis chemija apibrėžtis Fermentas, skaidantis laktozę. atitikmenys: angl. lactase rus. лактаза …   Chemijos terminų aiškinamasis žodynas

  • Lactase persistence — is the continued activity of the enzyme lactase in adulthood. Since lactase s only function is the digestion of lactose in milk, in most mammalian species the activity of the enzyme is dramatically reduced after weaning.[1] However in some human… …   Wikipedia

  • Lactase deficiency — Not enough of an enzyme called lactase in the small intestine to digest lactose, a prominent component of milk and most other dairy products. Lactose is sometimes also used as an ingredient in other foods, so anyone with lactase deficiency should …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”