Lactose

Lactose is a disaccharide that is made up of galactose and glucose molecules. Lactose makes up around 2-8% of the solids in milk. The name comes from the Latin word for milk, plus the -ose ending used to name sugars. Lactose is found in some milk products.

Infant mammals are fed on by milk from their mothers. To digest it, an enzyme called lactase cleaves the lactose into its two subunits glucose and galactose for absorption.

• Study Detects Recent Instance of Human Evolution (Finding that lactose tolerance is a recent change)

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