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': 'Fluoride is used in \nSelect and explain. \nA. Blood glucose estimation samples, B. Urine glucose estimation samples, C. Both 1 & 2, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The\xa0high\xa0energy\xa0compound\xa0phosphoenol\xa0pyruvate\xa0is\xa0generated from 2-phosphoglycerate by\xa0the\xa0enzyme enolase. This enzyme requires Mg2+ or Mn2+\xa0and\xa0is inhibited\xa0by fluoride.\xa0For blood\xa0 glucose\xa0estimation\xa0in\xa0the laboratory, fluoride is added to the blood to prevent glycolysis by the cells, so that blood glucose is correctly estimated.', 'role': 'assistant'}]