Which term describes a molecule composed of two monosaccharides?

Which term describes a molecule composed of two monosaccharides?

• A. Disaccharide
• B. Polysaccharide
• C. Monosaccharide
• D. Nucleotide

Answer: (A)

A molecule formed by joining two monosaccharides is called a disaccharide. This kind of carbohydrate contains exactly two sugar units linked by a glycosidic bond. When you hydrolyze a disaccharide, the bond breaks and you get two monosaccharides. Examples include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two glucose units). The term disaccharide distinguishes it from larger carbohydrate polymers and from a single sugar unit. A polysaccharide has many sugar units (like starch or cellulose), a monosaccharide is just one sugar unit, and a nucleotide is a different type of molecule comprising a sugar, phosphate, and a nitrogenous base.

A molecule formed by joining two monosaccharides is called a disaccharide. This kind of carbohydrate contains exactly two sugar units linked by a glycosidic bond. When you hydrolyze a disaccharide, the bond breaks and you get two monosaccharides. Examples include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two glucose units). The term disaccharide distinguishes it from larger carbohydrate polymers and from a single sugar unit. A polysaccharide has many sugar units (like starch or cellulose), a monosaccharide is just one sugar unit, and a nucleotide is a different type of molecule comprising a sugar, phosphate, and a nitrogenous base.