This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Which of the following are metalloporphyrins? \nSelect and explain. \nA. Hemoglobin, B. Catalase, C. Bilirubin, D. Cytochrome', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hemoglobin consists of heme and globin.in which heme pa consists of porphyrin ring and metallic iron.Ref: DM Vasudevan - Textbook of Biochemistry for Medical Students, 7th edition, page no: 271', 'role': 'assistant'}]