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': 'Cystathionine lyase requires which cofactor ? \nSelect and explain. \nA. Thymine, B. Riboflavin, C. Pyridoxine, D. Niacin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Hydrolytic cleavage (hydrolysis) of cystathionine forms Homoserine plus cysteine.This reaction is catalyzed by the enzyme cystathionine lyase (cystathionase), which requires cofactor pyridoxal phosphate (active form of pyridoxin).', 'role': 'assistant'}]