Questions: In a redox reaction electron are donated and accepted by molecules or atoms water is formed by all the extro protons coming together electron carriers, NADH and FADN2, pick up electrons from the ETS proteins are precursors for electron carriers an electron gradient is generated across the mitochondria inner membrane

The answer is the first one: In a redox reaction, electrons are donated and accepted by molecules or atoms.

Explanation for each option:

1. In a redox reaction, electrons are donated and accepted by molecules or atoms.

   • This statement is correct. Redox reactions involve the transfer of electrons between two species. One species loses electrons (oxidation), and the other gains electrons (reduction).

2. Water is formed by all the extra protons coming together.

   • This statement is incorrect. Water is formed when protons (H⁺ ions) combine with electrons and oxygen at the end of the electron transport chain in cellular respiration, not just by protons coming together.

3. Electron carriers, NADH and FADN2, pick up electrons from the ETS.

   • This statement is incorrect. NADH and FADH2 donate electrons to the electron transport chain (ETS), not pick them up from it. They are reduced forms of electron carriers that deliver electrons to the ETS.

4. Proteins are precursors for electron carriers.

   • This statement is incorrect. Electron carriers like NAD+ and FAD are not directly derived from proteins. They are coenzymes that assist in the transfer of electrons during metabolic reactions.

5. An electron gradient is generated across the mitochondria inner membrane.

   • This statement is correct but not directly related to the redox reaction itself. The electron transport chain creates a proton gradient across the inner mitochondrial membrane, which is used to produce ATP.

In summary, the correct answer is the first option, as it accurately describes the fundamental process of a redox reaction.