Question

Identify the correct sequence of cytochromes involved in ETS.

• A. \(\text{Cyt}\ c\rightarrow \text{Cyt}\ bc_{1}\rightarrow \text{Cyt}\ a\rightarrow \text{Cyt}\ a_{3}\)
• B. \(\text{Cyt}\ bc_{1}\rightarrow \text{Cyt}\ c\rightarrow \text{Cyt}\ a\rightarrow \text{Cyt}\ a_{3}\)
• C. \(\text{Cyt}\ a\rightarrow \text{Cyt}\ c\rightarrow \text{Cyt}\ bc_{1}\rightarrow \text{Cyt}\ a_{3}\)
• D. \(\text{Cyt}\ a_{3}\rightarrow \text{Cyt}\ c\rightarrow \text{Cyt}\ a\rightarrow \text{Cyt}\ bc_{1}\)

Hint:

Electrons go from complex III to cytochrome c, then to complex IV.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
From ubiquinol, electrons pass to the cytochrome \(bc_1\) complex (complex III).

Step 2: Next steps
Cytochrome c is a mobile carrier that takes electrons from complex III to complex IV. Complex IV has cytochromes a and \(a_3\), and electrons go from a to \(a_3\).

Step 3: Conclusion
The sequence is \(bc_1 \rightarrow c \rightarrow a \rightarrow a_3\).

Final Answer:
The sequence is Cyt bc1, Cyt c, Cyt a, Cyt a3. \[ \boxed{\text{(B) }\text{Cyt}\ bc_{1}\rightarrow \text{Cyt}\ c\rightarrow \text{Cyt}\ a\rightarrow \text{Cyt}\ a_{3}} \]