This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
Amobarbital inhibit electron transpo 
Select and explain. 
A. Complex I, B. Complex II, C. Complex III, D. Complex IV
A: Complex I
Answer: A: Complex I 
Explanation: Barbiturates such as amobarbital inhibit electron transpo Complex I by blocking the transfer from Fe-S to Q. At sufficient dosage, they are fatal in vivo. Reference: Harper; 30th edition; Page no: 132