Question

Terminal cytochrome of respiratory chain which donates electrons to oxygen is

• A. Cyt. b
• B. Cyt. c
• C. Cyt.$a_1$
• D. Cyt. $A_3$

Answer 1

The correct option is D Cyt. $A_3$

The ETS or Electron Transport System is formed by multiple complexes at different energy levels which in turn are formed by certain coenzymes and cytochromes. The coenzymes are the proton carriers and cytochromes are electron carriers in ETS. The terminal complex IV is formed by cyt. A and cyt. A3. Electron from cyt. A3 finally gets accepted by oxygen.

So the answer is 'Cyt. A3'.