This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins bonds and structure, Subject name: Biochemistry
[{'content': "Which of the following protein can't have quaternary structure? \nSelect and explain. \nA. Albumin, B. Immunoglobulin, C. Hemoglobulin, D. Collagen", 'role': 'user'}, {'content': 'Answer: A \nExplanation: For quaternary structure to be present you need more than one polypeptide chain Albumin is a single polypeptide. So, the highest structure it can have is teiary structure. Hemoglobin & Immunoglobulin are tetramer - option b and c are excluded. Collagen has the quaternary structure of quaer staggered arrangement - option d is excluded. fig:-Quaer stagger arrangement of tropocollagen', 'role': 'assistant'}]