What are the key products of the electron transport chain?

The correct answer highlights the primary products generated by the electron transport chain (ETC), which are water (H2O), adenosine triphosphate (ATP), and the oxidized forms of the electron carriers, NAD+ and FAD.

During cellular respiration, the electron transport chain is crucial for the transfer of electrons derived from NADH and FADH2, generated in earlier metabolic processes such as glycolysis and the citric acid cycle. As electrons are transferred through a series of protein complexes and mobile carriers within the inner mitochondrial membrane, a proton gradient is established. This gradient drives ATP synthesis as protons flow back into the mitochondrial matrix through ATP synthase, leading to the production of ATP.

Additionally, at the end of this chain, electrons combine with molecular oxygen (O2) and protons to form water (H2O), a vital step in completing the electron transport process and preventing the building up of electrons in the chain. The regeneration of NAD+ and FAD is also essential for maintaining the cycle of metabolism, as they can be reused in earlier stages of cellular respiration to accept electrons once more.

This option effectively summarizes the main outputs of the ETC, linking the processes of energy conversion and the breakdown of reducing