Final answer:
The electron transport chain proteins are embedded in the inner mitochondrial membrane in eukaryotic cells and in the cytoplasmic membrane in prokaryotic cells, facilitating ATP production through oxidative phosphorylation.
Step-by-step explanation:
The proteins of the electron transport chain (ETC) are located in the inner membrane of the mitochondria in eukaryotic cells, and in the cytoplasmic membrane of prokaryotic cells. Electrons from NADH and FADHâ‚‚ are passed through a series of redox reactions within the ETC, which generate energy used to create a proton gradient across the membrane. This proton gradient is then harnessed by ATP synthase to produce ATP through oxidative phosphorylation. The electron transport chain is a critical step in cellular respiration where the production of most ATP occurs, and its efficiency is a key component in the metabolism of cells performing aerobic respiration.