This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Which of the following is a peroxisomal free radical scavenger? 
Select and explain. 
A. Superoxide dismutase, B. Glutathione peroxidase, C. Catalase, D. Selenium
C: Catalase
Answer: C: Catalase 
Explanation: Ref Robbins 9/e p15 Catalase, present in peroxisomes, catalyzes the decom- position of hydrogen peroxide (2H2O2 - O2 + 2H2O). It is one of the most active enzymes known, capable of degrading millions of molecules of H2O2 per second. * Endogenous or exogenous antioxidants (e.g., vitamins E, A, and C and b-carotene) may either block the forma- tion of free radicals or scavenge them once they have formed.