Lactase

Lactase
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.
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SYN: β-d-galactosidase.

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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

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

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lac·tase (lakґtās) a β-galactosidase [EC 3.2.1.23] 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.

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  • 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

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  • 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

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  • 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

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