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': 'Which of the following does not cross the cell membrane \nSelect and explain. \nA. Glucose-6-phosphate, B. Glucose, C. Nitrous oxide, D. Carbon monoxide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Glucose-6-phosphate\xa0\n"Glucose-6-phosphate cannot diffuse out of muscle cells".\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 —Pankaj Naik\n\nGlucose-6-phosphate cannot diffuse out of the cell as such. First, it has to be converted to glucose by glucose-6-phosphatase which then diffuse out of the cells. This occurs in liver. Thus, glucose can be used by other tissues.\n\nMuscle cells does not contain glucose-6-phosphatase, glucose-6-phosphate cannot be converted to glucose and glucose-6-phosphate can only by utilized as a source of energy by only muscle itself.', 'role': 'assistant'}]