Monosaccharides join to form larger carbohydrates by which bond type?

• A. Peptide
• B. Glycosidic
• C. Phosphodiester
• D. Ester

Answer: (B)

Glycosidic bonds are the link that unites monosaccharides into larger carbohydrates. This covalent bond forms when the hydroxyl group of one sugar reacts with the anomeric carbon of another sugar in a dehydration synthesis, releasing a molecule of water. The result is an O-glycosidic linkage, which can be in different configurations (alpha or beta) depending on the orientation at the anomeric carbon. This type of bond is what holds disaccharides like maltose, lactose, and sucrose together, and it also builds polysaccharides such as starch, glycogen, and cellulose.

Peptide bonds join amino acids in proteins, phosphodiester bonds connect nucleotides in nucleic acids, and ester bonds are found in fats and other lipids. Those bonds are characteristic of other biomolecules, not the way sugars are linked to form carbohydrates.