Lactose is considered which type of sugar?

Lactose is classified as a disaccharide because it is composed of two monosaccharide units: glucose and galactose. Disaccharides are sugars formed when two monosaccharides are linked together through a glycosidic bond. In the case of lactose, this bond is specifically formed through a condensation reaction, where a molecule of water is removed. The structure of lactose allows it to be broken down into its monosaccharide components by the enzyme lactase during digestion. This classification distinguishes lactose from simple sugars, which are single-molecule sugars (monosaccharides), and complex sugars, which typically consist of long chains of monosaccharides (polysaccharides). Thus, the correct identification of lactose as a disaccharide highlights its biochemical structure and how it functions within the body.