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': 'Most common enzyme decient in urea cycle: \nSelect and explain. \nA. Arginase, B. Ornithine transcarbamoylase, C. Carbamoyl phosphate synthase I, D. Argininosuccinate synthetase', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Urea cycle defects result from\xa0 deficiency or total absence of the activity of any of the enzymes along the pathway, particularly carbamoyl phosphate synthase I (CPSI), ornithine transcarbamylase (OTC), argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL), arginase (ARG) or a deficiency of the co-factor N-acetylglutamate (NAG).\xa0\xa0\nUrea cycle disorders\nDisorder\nInheritance\nEnzyme defect Clinical Manifestations Hyperammonemia I Inborn defect CPS I\n● Ammonia toxicity\n● Ataxa\n● Protein intolerance Hyperammonemia II X-linked deciency OTC\n● Ammonia toxicity\n● Increases levels of glutamine, ornithine and ammonia in the blood\nCitrullinemia\nDouble recessive\nArgininosuccinate synthetase\n● Increased levels of citrutlhe in the blood\n● Hyperammonemia\n● Mental retardation\nArgininosuccinic\naciduria\nDouble\nrecessive\nArginino succinate lyase\n● High levels of arginino-succinate in blood, urine andCSF\n● Mental retardation\n● Friable tufted hair\nArginemia\nArginase\n● Increased Arg levels in the blood, CSF and brain\n● Increased levels of amino acids transported by the COAL transporter', 'role': 'assistant'}]