Which of the following glycosaminoglycan contains iduronic acid?: (A) Hyaluronic acid, (B) Keratan sulfate I, (C) Keratan sulfate II, (D) Heparin
Answer is D. Option d : Heparin contains iduronic acid Glucuronic acid is the hexuronic acid present in most of the glycosaminoglycans. Iduronic acid is a component of Heparin Dermatan sulfate Heparin and Heparan sulfate both contain N-sulfo glucosamine sugar instead of N-acetyl glucosamine as sugar component. NOTE: Dermatan sulfate is made up of N-acetyl galactosamine + iduronic/glucuronic acid