Galactose

Galactose is a monosaccharide, similar in structure to glucose, with the same structural formula C₆H₁₂O_6.It is far less common in nature than glucose, however is dehydrated in a reaction with glucose to form lactose, a common disaccharide found in milk. Galactose is often described as a C4 epimer of glucose as although it has the same numbers of each atoms, the way that these atoms are arranged in space, (stereoisomerism), is different, and as such they are both non-superimposable mirror images of one another.