Question

Cytochrome c is a small protein attached to the

• A. outer surface of the outer mitochondrial membrane and acts as a mobile carrier for transfer of electrons between complex II and III
• B. inner surface of the outer mitochondrial membrane and acts as a mobile carrier for transfer of electrons between complex III and IV
• C. outer surface of the inner mitochondrial membrane and acts as a mobile carrier for transfer of electrons between complex III and IV
• D. inner surface of the inner mitochondrial membrane and acts as a mobile carrier for transfer of electrons between complex III and IV

Answer 1

Answer: (C)

The ETS contains various cytochromes. Cytochrome bc1 complex (complex III) and cytochrome aa₃ complex (complex IV) are attached to the inner mitochondrial membrane. Cytochrome c is a small protein attached to the outer surface of the inner membrane and acts as a mobile carrier for transfer of electrons between complex III and IV.