The ester linkage between fatty acids and glycerol is characteristic of which biomolecule category?

The ester linkage between fatty acids and glycerol is characteristic of which biomolecule category?

• A. Carbohydrates
• B. Nucleic acids
• C. Proteins
• D. Lipids

Answer: (D)

Esters between fatty acids and a glycerol backbone define lipids. In these molecules, each fatty acid attaches to glycerol via an ester bond formed by a dehydration reaction between the fatty acid’s carboxyl group and a glycerol hydroxyl group. This is what you see in triglycerides (three fatty acids on glycerol) and in phospholipids (two fatty acids plus a phosphate-containing head). Carbohydrates are built from sugars linked by glycosidic bonds, proteins from amino acids linked by peptide bonds, and nucleic acids from nucleotides linked by phosphodiester bonds. The presence of ester linkages here identifies lipids as the biomolecule category.

Esters between fatty acids and a glycerol backbone define lipids. In these molecules, each fatty acid attaches to glycerol via an ester bond formed by a dehydration reaction between the fatty acid’s carboxyl group and a glycerol hydroxyl group. This is what you see in triglycerides (three fatty acids on glycerol) and in phospholipids (two fatty acids plus a phosphate-containing head). Carbohydrates are built from sugars linked by glycosidic bonds, proteins from amino acids linked by peptide bonds, and nucleic acids from nucleotides linked by phosphodiester bonds. The presence of ester linkages here identifies lipids as the biomolecule category.