This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
[{'content': 'Intact peptide bond is necessary for which test? \nSelect and explain. \nA. UV diffraction, B. Ninhydrin, C. Diazo reaction, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ninhydrin, widely used for detecting amino acids, forms a purple product with -amino acids and a yellow product with the imine groups of proline and hydroxyl-proline.Ref: Harper 28th Ed. Page-20, Harper 27th Ed. Page: 20', 'role': 'assistant'}]