Lactose Identifiers Properties
CAS number 63-42-3
PubChem 6134
MeSH Lactose
Molecular formula C12H22O11
Molar mass 342.296
Except where provided otherwise, information are provided for materials in their traditional state(at 25°C, 100kPa)Infobox disclaimer and references

Lactose (likewise referred to as milk sugar) is a sugar which is uncovered many notably in milk. Lactose provides up around 2–8% of the solids in milk. The name comes from the Latin word for milk, plus the -ose ending offered to name sugars.




1 Chemistry



Lactose is a disaccharide that consists of β-D-galactose and also D-glucose molecules bonded through a β1-4 glycosidic linkage.

You are watching: What type of molecule lactose is and list its subunits


Lactose has a solubility of 1 in 4.63 measured %w/v. This equates to 0.216g of lactose dissolving conveniently in 1mL of water.

The solubility of lactose in water is 18.9049g at 25°C, 25.1484g at 40°C and 37.2149g at 60°C per 100g solution. Its solubility in ethanol is 0.0111g at 40°C and also 0.0270g at 60°C per 100g solution.<1>

Digestion of lactose

Infant mammals are fed on milk by their mothers. To digest it an enzyme dubbed lactase (β-D-galactosidase) is secreted by the intestinal villi, and also this enzyme cleaves the molecule right into its two subsystems glucose and galactose for absorption.

Since lactose occurs mostly in milk, in most mammals the production of lactase slowly decreases through maturity. However, production never before ceases completely; it is regulated by the existence of lactose in the diet, which in turn deactivates the repressor of the lac operon, enabling lactase to be synthesized. In various other words, lactose induces the synthesis of the enzyme which breaks it dvery own.<2> (See also: gene expression.)

Many kind of world via family tree in Europe, the Middle East, India, or parts of East Africa, keep normal lactase production into adulthood. In many kind of of these cultures mammals such as livestock, goats, and also sheep are milked for food. Hence, it remained in these areas that genes for lifelengthy lactase production first progressed.

See more: The Youngest Rocks On The Ocean Floor Are Located ? The Age Of The Ocean Floor



General: Geometry: Small/Large: Trioses: Tetroses: Pentoses: Hexoses: Disaccharides: Polymers: Glycosaminoglycans: Aminoglycosides:
Aldose | Ketose | Pyranose | Furanose
Triose | Tetincreased | Pentose | Hexose | Heptose | Cyclohexane condevelopment | Anomer | Mutarotation
Glyceraldehyde | Dihydroxyacetone | Erythrose | Threose | Erythrushed | Sedoheptulose
ketotriose | Aldotriose
Erythrushed | Erythincreased | Threose
Arabinose | Deoxyribose | Lyxose | Ribose | Ribushed | Xyshed | Xylulose
Glucose | Galactose | Mannose | Gushed | Idose | Tashed | Alshed | Altrose | Fructose | Sorbose | Tagatose | Psicose | Fucose | Rhamnose
Sucincreased | Lactose | Trehashed | Maltose
Glycogen | Starch (Amyshed | Amylopectin) | Cellulose | Chitin | Stachyose | Inulin | Dextrin
Heparin | Chondroitin sulfate | Hyaluronan | Heparan sulfate | Dermatan sulfate | Keratan sulfate
Kanamycin | Streptomycin | Tobramycin | Neomycin | Paromomycin | Apramycin | Gentamicin | Netilmicin | Amikacin

This write-up is licensed under the GNU Free Documentation License. It uses product from the Wikipedia post "Lactose". A list of authors is available in Wikipedia.


Read what you need to recognize around our sector portal