<prompt> Barbiturates act on which step of mitochondrial respiratory chain:Complex I to Co-enzyme QCoenzyme Q to Complex IIIComplex II to Coenzyme QCytochrome C to Complex IV  <response>: option a : Barbiturates such as amobarbital inhibit electron transpo Complex I by blocking the transfer from complex I to Coenzyme Complexes Inhibitors of ETC Complex I NADH-CoQ reductaseNADH dehydrogenase Rotenone, Phenobarbitone, Amobarbital, Piericidin A Complex II Succinate CoQ reductase Malonate 3C Carboxin Fungicide TTFA Trienoyl Tri Fluoro Acetone Complex III Cyt c reductase Phenoformin Antimycin A BAL British Anti Lewisite or Dimercaprol Complex IV Cyt c oxidase CO Cyanide CN, H2S, Sodium Azide Uncouplers of ETC: Dinitrophenol, Thermogenin ADP to ATP conversion is inhibited by: Oligomycin ADP to ATP transfer is inhibited by: Atractyloside 