Beta-galactoside
Encyclopedia
A β-galactoside is a type of galactoside
in which the glycosidic bond
lies above the plane of the galactose
residue. The most commonly recognized and used β-galactoside in biochemistry is Lactose
. However, other chemicals, such as ONPG, are known, but these are typically synthesized for biochemical assays. An enzyme that breaks the β-galactoside bond is called a β-galactosidase.
Galactoside
A galactoside is a glycoside containing galactose. The H of the OH group on carbon-1 of galactose is replaced by an organic moiety.Depending on whether the glycosidic bond lies "above" or "below" the plane of the galactose molecule, galactosides are classified as α-galactosides or β-galactosides....
in which the glycosidic bond
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....
lies above the plane of the galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....
residue. The most commonly recognized and used β-galactoside in biochemistry is Lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
. However, other chemicals, such as ONPG, are known, but these are typically synthesized for biochemical assays. An enzyme that breaks the β-galactoside bond is called a β-galactosidase.