Question

Cyanide resistant pathway is _____.

• A. anaerobic respiration
• B. aerobic respiration
• C. Both (a) and (b)
• D. None of these

Answer 1

The correct option is A anaerobic respiration

Cyanide is a deadly poison of respiration and inhibit the activity of cytochrome –c oxidase complex (which contains cytochrome a and cytochrome a₃) of the electron transport chain in aerobic respiration. Thus, no proton gradient will be established and no ATP will be formed. As the reoxidation of NADH and FADH₂ ceases, due to the blockage of the ETC, the availability of hydrogen acceptors like NAD⁺ and FAD for Kreb’s cycle and glycolysis pathways also ceases. Thus stopping respiration. In anaerobic respiration the electron acceptors NAD+ and FADH2 can be regenerated anaerobically and therefore anaerobic respiration is a cyanide resistant pathway.