Lactase is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. Lactase (EC 3.2.1.23) is involved in the hydrolysis of lactose in to constituent galactose and glucose monomers. Not all β-galactosidase hydrolysis lactose, but those that can quilify as lactase enzymes. In humans, lactase is produced in the digestive tract. Deficiency of the enzyme causes lactose intolerance; and most humans are normally lactose intolerant as adults. Persistant lactase production as adults in humans is probably not due to mutations within the lactase gene, but to mutations outside the gene in control regions that regulate the expression of the lactase gene. A β-galactosidase is a type of hydrolase that that catalyzes the cleavage of terminal, β-linked, nonreducing galactose residues from a variety of substrates, including ganglioside GM1, lactosylceramides, lactose, and various glycoproteins and oligosaccharides. ... Beta (upper case Î’, lower case β) is the second letter of the Greek alphabet. ... Galactose (also called brain sugar) is a type of sugar found in dairy products, in sugar beets and other gums and mucilages. ... EC numbers (Enzyme Commission numbers) are a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ... Lactose is a disaccharide that makes up around 2-8% of the solids in milk. ... Glucose (Glc), a simple monosaccharide sugar, is one of the most important carbohydrates and is used as a source of energy in animals. ... In chemistry, a monomer (from Greek mono one and meros part) is a small molecule that may become chemically bonded to other monomers to form a polymer. ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and...

Characteristics

Lactase has an optimum temperature of about 48 °C for its activity and an optimum pH of 6.5. In humans, the gene is localised on the second chromosome (2q21). Bacterial and Archea lactase lack a membrane binding domain and free float around the cell, these also tend to be more general β-galactosidase that will cleave more then just lactose. Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The title of this article is shown beginning with a capital letter due to technical restrictions. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Figure 1: Chromosome. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria is also the fictional name of a warring nation under Benzino Napaloni as dictator, in the 1940 film The Great Dictator... Phyla / Classes Phylum Crenarchaeota Phylum Euryarchaeota     Halobacteria     Methanobacteria     Methanococci     Methanopyri     Archaeoglobi     Thermoplasmata     Thermococci Phylum Korarchaeota Phylum Nanoarchaeota The Archaea are a major group of prokaryotes. ...

Industrial use

Lactase produced commercially can be extracted from yeast fungi such as Kluyveromyces fragilis. Its primary commercial use is to break down lactose in milk to make it suitable for people with lactose intolerance. Lactase is also used in the manufacture of ice cream. Because glucose and galactose are sweeter than lactose, lactase produces a more pleasant taste. Lactose also crystallises at the low temperatures of ice cream; however, its constituent products stay liquid and contribute to a smoother texture. Lactase is used in the conversion of whey into syrup. Divisions Chytridiomycota Deuteromycota Zygomycota Glomeromycota Ascomycota Basidiomycota Yellow fungus Fungus growing on a tree in Borneo A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... Kluyveromyces fragilis is a yeast fungus. ... Missing image Ice cream is often served on a stick Boxes of ice cream are often found in stores in a display freezer. ... Whey or milk plasma is the liquid remaining after milk has been curdled and strained; it is a by-product of the manufacture of cheese or casein and has several commercial uses. ...

External links

• OMIM 603202
• E. coli β-galactosidase: PDB 1DPO

Also used to screen for blue white colonies into the MCS of various plasmid vectors in E.Coli or other bacteria, as the lacZ gene is destroyed The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Protein Data Bank (PDB) is a repository for 3-D structural data of proteins and nucleic acids. ...