What occurs during the electron transport chain in organic chemistry?

• A. Amino acids are synthesized from nitrogen and carbon sources.
• B. Electrons are transferred through a series of proteins to produce $\mathrm{ATP}$.
• C. Glucose is broken down into $\mathrm{pyruvate}$.
• D. Carbon dioxide is fixed into $\mathrm{glucose}$.

Answer: (B)

Verified step by step guidance

1. Begin by understanding the electron transport chain (ETC) as a series of protein complexes located in the inner mitochondrial membrane.
2. Recognize that the primary function of the ETC is to transfer electrons from electron donors like NADH and FADH2 to electron acceptors such as oxygen, through a series of redox reactions.
3. Note that as electrons move through the chain, protons are pumped across the mitochondrial membrane, creating a proton gradient.
4. Understand that this proton gradient generates a chemiosmotic potential, which is used by ATP synthase to synthesize ATP from ADP and inorganic phosphate.
5. Remember that the electron transport chain is a crucial step in cellular respiration, ultimately leading to the production of ATP, the energy currency of the cell.