This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Biochemistry
Most powerful chain breaking antioxidant: 
Select and explain. 
A. Vitamin C, B. Alpha - tocopherol, C. Catalase, D. Glutathione peroxidase
B: Alpha - tocopherol
Answer: B: Alpha - tocopherol 
Explanation: Alpha- tocopherol is most powerful chain breaking anti-oxidants. 2 Classes of antioxidants Chain breaking anti - oxidants : (They interfere with chain propagation) Alpha - tocopherol Beta - carotene Vitamin C Super oxide dismutase (SOD) Uric acid/Urate Polyphenols Preventive antioxidants: (They reduce the rate of chain initiation) Glutathione peroxidase Catalase Ceruloplasmin & transferrin (Chelate metal ions)