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': 'The anion gap in a healthy indiviual is around ___. \nSelect and explain. \nA. 5 mEq/L, B. 15 mEq/L, C. 20 mEq/L, D. 25 mEq/L', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Anion Gap:\n\nThe total concentration of cation and anions in the body fluids expressed as mEq/L.\nThis is required to maintain electrical neutrality.\nThe commonly measured electrolytes in the plasma are Na+, K+, Cl-\xa0and HCO3-\nSodium and potassium together accounts for 85% of the cations, whereas chloride and bicarbonate account for 86% of the anions.\nHence, there is always a difference between the measured cations and anions.\nIt is due to the presence of protein, anions, sulphates, phosphates.\nAnion gap is defined as the difference in between the total concentration of measured cation (Na+ and K+) and that of measured anion (Cl- and HCO3-).\n\n\tNA+ + K+ = Cl- + HCO3-+ A-\n\t136 + 4 = 100 + 25 + A-\n\tA- = 15\xa0mEq/L.\n\t\xa0\nThe anion gap in\xa0a healthy individual is around 15 mEq/L\xa0(range of 8-18 mEq/L)', 'role': 'assistant'}]