Which bond type links fatty acids to glycerol in lipids?

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

Answer: (A)

Linking fatty acids to glycerol in lipids occurs through an ester bond. The carboxyl group of each fatty acid reacts with a hydroxyl group on glycerol in a condensation reaction, forming an ester linkage and releasing water. In triglycerides, three fatty acids esterify to the three hydroxyl groups of glycerol, creating three ester bonds that anchor the fatty acids to the glycerol backbone. This ester connection is what lipases break during digestion to release fatty acids for energy. By contrast, peptide bonds join amino acids in proteins, glycosidic bonds link sugar units in carbohydrates, and phosphodiester bonds connect nucleotides in nucleic acids (and aren’t the linkage that attaches fatty acids to glycerol in lipids).