As nouns the difference between galactose and lactase

is that galactose is (carbohydrate) a monosaccharide found, along with lactose, in dairy products, and is synthesized by the body where it is found associated with glycolipids and glycoproteins while lactase is (enzyme|organic compound) a β-galactosidase enzyme that is involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers.