In ETS, electrons moves from

Options

A. NADH to `O_(2)`
B. FADH to `O_(2)`
C. `H_(2)O` to `O_(2)`
D. 1 and 2

Answer

**Step-by-Step Solution:**

1. **Understanding the Electron Transport Chain (ETS):**
- The Electron Transport Chain (ETS) is a series of protein complexes located in the inner membrane of the mitochondria. It plays a crucial role in cellular respiration by facilitating the transfer of electrons.

2. **Identifying Electron Donors:**
- The primary electron donors in the ETS are NADH and FADH2. These molecules are generated during earlier stages of cellular respiration, such as glycolysis and the Krebs cycle.

3. **Electron Flow:**
- In the ETS, electrons are transferred from NADH and FADH2 to various electron carriers. This transfer occurs in a specific sequence, where electrons move from higher energy states to lower energy states.

4. **Final Electron Acceptor:**
- The electrons ultimately reduce oxygen (O2) to form water (H2O), which is the final electron acceptor in the chain.

5. **Conclusion:**
- Therefore, the correct answer to the question "In ETS, electrons move from" is that they move from both NADH and FADH2 to oxygen (O2), which leads us to the conclusion that the correct option is "both 1 and 2."

**Final Answer:**
- The correct option is 4, both 1 and 2.

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