Answer:
Lactase is an enzyme which breaks the lactose sugar into its two components called galactose and glucose.
The lactase enzyme is specific for the lactose sugar as the specificity of the enzyme depends on the structure of the enzyme which is the active site or the attachment site for the substrate.
This precise compatibility of the active site with the substrate molecule or the lactose molecule in the given case is responsible for the specificity.
The three-dimensional characteristics of the molecule provide for a precise interaction with the active site.
Lactase’s function is to break down lactose into the two simple sugars it is made up of, glucose and galactose. Breaking down lactose into its simple sugars makes it possible for it to be absorbed via the small intestine and used by the body.