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
[{'content': 'Which of the following amino acids in a protein commonly acts as a potential O-Glycosylation site for attachment of an oligosaccharide unit - \nSelect and explain. \nA. Glutamine, B. Cysteine, C. Serine, D. Asparagine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: O-glycosylation:- Addition of oligosaccharide to hydroxyl chain of serine or threonine.\nN-glycosylation:- Addition of oligosaccharide to the amide nitrogen of asparagine.', 'role': 'assistant'}]