This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Which Mucopolysaccharide does not contain Uronic acid 
Select and explain. 
A. Heparin, B. Dermatan sulphate, C. Keratan sulphate, D. Hyaluronic acid
C: Keratan sulphate
Answer: C: Keratan sulphate 
Explanation: Keratan sulphate has N-acetyl glucosamine and galactose. It does not contain uronic acid.
It general all Mucopolysaccharides, contain a disaccharide repeat unit having aminosugar and Uronic acid.