Flow of electrons in ETS is

Options

A. Cytochrome `to` CoQ
B. CoQ `to` Cytochrome
C. Cytochrome `to` FMN
D. Cytochrome`to F_(0)F_(1)`

Answer

### Step-by-Step Solution:

1. **Understanding Electron Transport System (ETS)**:
- The Electron Transport System (ETS) is a series of protein complexes and other molecules that transfer electrons from electron donors to electron acceptors via redox reactions. This process is crucial for ATP production in cellular respiration.

2. **Identifying the Components of ETS**:
- The main components involved in the electron transport chain include:
- NADH and FADH2 (electron donors)
- FMN (Flavin Mononucleotide)
- Coenzyme Q (CoQ or ubiquinone)
- Cytochromes (such as cytochrome b, c, and a)
- ATP synthase (F0, F1 complex)

3. **Flow of Electrons**:
- The flow of electrons in the ETS starts from the electron donors (NADH and FADH2) and progresses through various carriers:
- First, electrons are transferred from NADH to FMN.
- Next, electrons flow from FMN to Coenzyme Q (CoQ).
- After CoQ, electrons are passed to cytochromes (cytochrome b, c, and a).
- Finally, the electrons are transferred to oxygen, the final electron acceptor.

4. **Correct Sequence of Electron Flow**:
- Based on the components and their interactions, the correct sequence of electron flow in the ETS is:
- Coenzyme Q → Cytochrome

5. **Conclusion**:
- Therefore, the correct answer to the question regarding the flow of electrons in the ETS is option 2: **Coenzyme Q to Cytochrome**.