Disaccharides are formed from which type of reaction?

• A. Hydrogenation
• B. Condensation
• C. Oxidation
• D. Reduction

Answer: (B)

Disaccharides are formed when two monosaccharides join together to create a glycosidic bond through a condensation (dehydration synthesis) reaction. In this process, the two sugar units lose a water molecule as they link, so a bond forms and a disaccharide is produced. This is the same type of reaction that links many carbohydrate units to build larger polysaccharides, with hydrolysis being the reverse: water is added to break the bond.

Hydrogenation, oxidation, and reduction describe different chemical changes—adding hydrogen, introducing oxygen/oxidation, or adding electrons, respectively—not the bond-forming process that creates disaccharides.