Home > Galactose

Galactose is a type of sugar found in milk product s and sugar beets. It is also made by the body. It is considered a nutritive sweetener because it has calories.

Galactose is a monosaccharide constituent, together with glucose, of the disaccharide lactose. The hydrolysis of lactose to glucose and galactose is catalyzed by the enzyme beta-galactosidase, a lactase.

Individuals who lack this enzyme are ' lactose intolerant' and unable to realize the nutritive potential of milk sugars. The lactose then passes to the large intestine where it is digested by bacteria, producing gas and flatulence.

External links:

• Glycogen Biosynthesis & Galactose Pathway
• Galactose metabolism - Reference pathway
• Picture of galactose crystals

1 Structure

The first and last -OH groups point the same way and the second and third -OH groups point the other way.

1.1 Isomerism

D-Galactose has the same configuration at its penultimate carbon as D- glyceraldehyde.

2 Reactions

2.1 HydrolysisHydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. This is distinct from a hydration reaction, in which water molecules are added to a substance, but no cleavage occurs. Types Hydrolysis

Galactose is hydrolysed by lactaseLactase (or beta;-galactosidase is the enzyme involved in the hydrolysis of lactose to galactose and glucose. Lactase produced commercially can be extracted from yeast fungi such as Kluyveromyces fragilis''. Its primary commercial use is to break down lac.