The electron transport chain (ETC) takes place on the inner mitochondrial membrane in eukaryotic cells. This membrane hosts a series of protein complexes and molecules that transfer electrons from donors like NADH and FADH2 to oxygen, the final electron acceptor, while pumping protons to create an electrochemical gradient used to synthesize ATP
. In photosynthetic eukaryotes, a similar electron transport chain occurs in the thylakoid membrane of chloroplasts, driven by light energy
. In summary:
- Eukaryotic cells (aerobic respiration): Inner mitochondrial membrane
- Photosynthetic eukaryotes: Thylakoid membrane of chloroplasts
- Prokaryotes: Varies, but always associated with a membrane to generate a proton gradient
Thus, the primary location for the electron transport chain in most eukaryotic cells is the inner mitochondrial membrane.
