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: Forensic Medicine
[{'content': 'Which of the following enzyme is affected in cyanide poisoning? \nSelect and explain. \nA. G-6-P dehydrogenase deficiency, B. Isomerase, C. Cytochrome oxidase, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cyanide inhibits the action of cytochrome oxidase and carbonic anhydrase. It blocks the final step of oxidative phosphorylation and prevents the formation of ATP and its use as energy source. Cyanide acts by reducing the oxygen carrying capacity of blood, and by combining with the ferric iron atom of intracellular cytochrome oxidase, preventing the uptake of oxygen for cellular respiration. Ref: The Essentials of Forensic Medicine and Toxicology by KS Narayan Reddy, 27th edition, Page 558-559.', 'role': 'assistant'}]