lactase
Sign in to saveKey facts
- Enzyme.Name
- Glycosylceramidase(Phlorizin hydrolase)
- Enzyme.EC_number
- 3.2.1.62
- Enzyme.CAS_number
- 9033-10-7
- Enzyme.GO_code
- 0017042
- Enzyme.image
- 1jyn.jpg
- Enzyme.width
- 270
- Enzyme.caption
- E. coli lactase tetramer.
- Protein.Name
- Lactase
- Protein.Symbol
- LCT
- Protein.AltSymbols
- LAC; LPH; LPH1
- Protein.HGNCid
- 6530
- Protein.Chromosome
- 2
- Protein.Arm
- q
- Protein.Band
- 21
- Protein.ECnumber
- 3.2.1.108
- Protein.OMIM
- 603202
- Protein.EntrezGene
- 3938
- Protein.RefSeq
- NM_002299
via Wikipedia infobox
Article
12 sectionsContents
- The animal (including human) versions
- Structure and biosynthesis
- Genetic expression and regulation
- Mechanism
- Non-animal lactases and their uses
- Added to food
- Ingested
- Biotechnology
- See also
- Notes
- References
- External links
Lactase () is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose, simple sugars that can be absorbed into the bloodstream through an animal's intestines. A lactase is a type of β-galactosidase because it breaks down the β-glycosidic bond in D-lactose. The chemical reaction it catalyzes is: C12H22O11 + H2O → C6H12O6 + C6H12O6 + heat. lactose + H2O → β-D-galactose + D-glucose
The only human gene encoding a lactase is LCT or lactase-phlorizin hydrolase (alternative symbol LPH). LCT has a lactase domain and a phlorizin hydrolase domain. It is encoded on chromosome 2. Lactase is found in the brush border of the small intestine of humans and other mammals. People without the mutation allowing production of functional LCT to continue past infancy may experience the symptoms of lactose intolerance after consuming milk products.