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: Pathology
Organelle where H202 is produced and destroyed is? 
Select and explain. 
A. Peroxisome, B. Lysosome, C. Golgi body, D. Ribosome
A: Peroxisome
Answer: A: Peroxisome 
Explanation: Ans. is 'a' i.e., Peroxisome Peroxisome is a membrane bound organellel found in all eukaryotic cells. "Peroxisomes contain a group of enzymes that oxidize a variety of substrates and thereby form hydrogen peroxide. The H202 thus formed is efficiently decomposed within the organelle by catalase which is present in high concentration". Lysosomes can only form H,02 - They cannot degrade H202. Remember H202 is produced as well as destroyed in mitochondria and cytosol. It is produced from superoxide by enzyme SOD. It is destroyed by glutathione peroxidase.