This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification of carbohydrate, Subject name: Biochemistry
[{'content': 'All of the following are the features of glycoproteins, except : \nSelect and explain. \nA. Highly-branched oligosaccharide, B. Presence of amino sugar, C. Absence of glucuronic acid, D. Presence of disaccharide repeat unit', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Option d, i.e., the presence of disaccharide repeat unit is a feature of proteoglycans. Glycoprotein Proteoglycans Oligosaccharide chains sho ,highly branched long, unbranched Components Amino sugars are present. Uronic acid is absent. Amino sugars and uronic acid are present. Disaccharide unit No repeating disaccharide unit. Disaccharide repeat unit (-Amino sugar-Hexuronic acid-) is present Site Cell surface proteins and secretory proteins are glycoproteins Connective tissue proteins are proteoglycans.', 'role': 'assistant'}]