Question

Given below are two statements : Statement I : Hydrogen Sulphide interfere with cellular respiration by inhibiting the action of cytochrome oxidase. Statement II : In Hydrogen Sulphide poisoning post mortem staining is of cherry red colour. In the light of the above statements, choose the most appropriate answer from the options given below :

• A. \( \text{Both Statement I and Statement II are correct} \)
• B. \( \text{Both Statement I and Statement II are incorrect} \)
• C. \( \text{Statement I is correct but Statement II is incorrect} \)
• D. \( \text{Statement I is incorrect but Statement II is correct} \)

Hint:

\textbf{Forensic Toxicology: Hydrogen Sulphide vs. Carbon Monoxide Poisoning.} It is important to differentiate the post-mortem findings in \(H_2S\) and CO poisoning. While both are asphyxiants, \(H_2S\) causes a greenish discoloration, and CO leads to a characteristic cherry red lividity.

Answer 1

The Correct Option is C

Let's analyze each statement regarding Hydrogen Sulphide poisoning: Statement I: Hydrogen Sulphide interfere with cellular respiration by inhibiting the action of cytochrome oxidase. Hydrogen Sulphide (\(H_2S\)) is a potent inhibitor of cytochrome c oxidase, a key enzyme in the mitochondrial electron transport chain responsible for cellular respiration. By binding to this enzyme, \(H_2S\) prevents the utilization of oxygen by cells, leading to histotoxic hypoxia. Therefore, Statement I is correct. Statement II: In Hydrogen Sulphide poisoning post mortem staining is of cherry red colour. Cherry red post-mortem staining is characteristic of carbon monoxide (CO) poisoning, where CO binds strongly to hemoglobin, forming carboxyhemoglobin, which has a bright red color. In Hydrogen Sulphide poisoning, the post-mortem staining is typically a greenish discoloration due to the formation of sulfhemoglobin or the reaction of sulfides with blood pigments. Therefore, Statement II is incorrect. In conclusion, Statement I is correct, but Statement II is incorrect.