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': 'The structural proteins are involved in maintaining the shape of a cell or in the formation of matrices in the body. The shape of these proteins is \nSelect and explain. \nA. Globular, B. Fibrous, C. Stretch of beads, D. Planar', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Collagen is the most abundant of the fibrous proteins that constitute more than 25% of the protein mass in the human body. Other prominent fibrous proteins include keratin and myosin. These fibrous proteins represent a primary source of structural strength for cells (i.e., the cytoskeleton) and tissues.Ref: Harper 28th Ed. Page-40, Harper 27th Ed. Page: 38', 'role': 'assistant'}]