This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Free Radical Injury, Subject name: Pathology
[{'content': 'Enzyme that protects the brain from free radical injury is: \nSelect and explain. \nA. Myeloperoxidase, B. Superoxide dismutase, C. NADPH oxidase, D. Hydroxylase', 'role': 'user'}, {'content': 'Answer: B \nExplanation: - Superoxidase dismutases (SODs) are found in many cell types and conve O2 radicals into hydrogen peroxide This group of enzymes includes:- Manganese-SOD localized in mitochondria Copper-zinc- SOD found in the cytosol. - One of the earliest discovered hereditary forms of Amyotrophic lateral sclerosis (ALS) has mutations in the gene encoding copper-zinc superoxide dismutase (SOD1) on chromosome 21; this variant accounts for about 20% of familial cases.', 'role': 'assistant'}]