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': 'Vit B 12 is absorbed in \nSelect and explain. \nA. Stomach, B. Deudenum, C. Ileum, D. Colon', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The\xa0 cobalamin-lF complex travels through the gut. The complex binds to specific receptors on the surface of the mucosal cells of the ileum. The binding of the complex and entry of B12 into the mucosal cells is mediated by Ca2+ ions. In the\xa0 mucosal\xa0 cells,\xa0 B12\xa0 is\xa0 converted\xa0 to methyf cobalamin.\xa0lt is then transported in the circulation in\xa0 a\xa0 bound form to\xa0 proteins namely\xa0 transcobalamins.', 'role': 'assistant'}]