Question

The last or terminal cytochrome in respiratory chain is

• A. Cyt b
• B. Cyt $a_3$
• C. Cyt a
• D. Cyt c

Answer 1

The correct option is B Cyt $a_3$

The last or terminal cytochrome in respiratory chain is cytochrome $a_3$. Cytochrome $a_3$ contains both iron and copper. In this, iron picks the electrons and through Cu, it hands over electron to oxygen. So, cytochrome $a_3$ is called as the terminal electron donor.

So, the correct answer is option B.