Final answer:
Sucrose is classified as a disaccharide because it consists of two monosaccharides, glucose and fructose, bonded via a glycosidic linkage. This union is the result of a dehydration reaction that forms sucrose, commonly known as table sugar.
Step-by-step explanation:
Sucrose is a disaccharide because it is composed of two monosaccharide molecules, glucose and fructose, which are linked together by a glycosidic bond. Specifically, sucrose consists of a molecule of D-glucose (in pyranose form) and D-fructose (in furanose form) joined by an α-1, β-2-glycosidic linkage. This bond is formed through a condensation reaction known as a dehydration reaction, in which a molecule of water is released as the result of the bond formation between the oxygen on the glucose and the carbon on the fructose.
Common disaccharides besides sucrose include lactose, found naturally in milk and comprising glucose and galactose, and maltose, or malt sugar, which is formed from two glucose molecules. These disaccharides, including sucrose, are important in various biological processes and dietary functions. Sucrose, commonly referred to as table sugar, plays a central role in metabolism as it can be broken down into its constituent monosaccharides, which are directly absorbed into the bloodstream during digestion.