Which one of the following is the correct sequence of electron transport in Mitochondria?

Options

A. (a) NADH to UQ to Cyt b to cyt c_1 to Cyt toCyt a to Cyt a_3 to O_2`
B. (b) NADH to Cyt a to Cyt a_3 to UQ to Cytb to Cyt c_1 to Cyt c to O_2`
C. (c) NADH to UQ to Cyt b to Cyta to Cyt a_3 to Cyt c to Cytc_1 to O_2`
D. (d) NADH to Cyt b to Cyt c_1 to Cyt c to UQ to Cyt a to Cyt a_3 to O_2`

Answer

To determine the correct sequence of electron transport in mitochondria, we need to understand the components involved in the electron transport chain (ETC) and their order of operation. Here’s a step-by-step breakdown of the process:

### Step-by-Step Solution:

1. **Identify the Components of the Electron Transport Chain:**
- The main components involved in the electron transport chain in mitochondria include:
- Complex I (NADH dehydrogenase)
- Complex II (Succinate dehydrogenase)
- Ubiquinone (Coenzyme Q)
- Complex III (Cytochrome bc1 complex)
- Cytochrome C
- Complex IV (Cytochrome c oxidase)
- Molecular Oxygen (O2)

2. **Understanding the Flow of Electrons:**
- The flow of electrons begins with NADH, which donates electrons to Complex I.
- From Complex I, electrons are transferred to Ubiquinone (Coenzyme Q).
- Ubiquinone then carries the electrons to Complex III.
- In Complex III, electrons are passed to Cytochrome C.
- Cytochrome C then transports the electrons to Complex IV.
- Finally, electrons are transferred to molecular oxygen, which is the final electron acceptor.

3. **Assembling the Sequence:**
- Based on the flow of electrons, the correct sequence is:
- NADH → Ubiquinone → Complex III (Cytochrome b and Cytochrome C1) → Cytochrome C → Complex IV (Cytochrome a and Cytochrome a3) → Molecular Oxygen.

4. **Evaluating the Options:**
- Now, we can evaluate the provided options to find the correct sequence.
- The correct sequence corresponds to the first option:
- NADH → Ubiquinone → Cytochrome b → Cytochrome C1 → Cytochrome C → Cytochrome a → Cytochrome a3 → Molecular Oxygen.

5. **Conclusion:**
- After analyzing all options, the correct sequence of electron transport in mitochondria is confirmed to be the first option.

### Final Answer:
The correct sequence of electron transport in mitochondria is:
**NADH → Ubiquinone → Cytochrome b → Cytochrome C1 → Cytochrome C → Cytochrome a → Cytochrome a3 → Molecular Oxygen.**