In bacterial and archaeal cells, the electron transport chain is located in the whereas in eukaryotic cells, the electron transport chain is located in the .

Cell membrane of prokaryotes and Inner mitochondria of eukaryotes

Explanation:

Electron transport chain is a part of oxidative phosphorylation which is the third step of aerobic cellular respiration in living organisms. The ETC is a complex of proteins and mobile electron carriers. It occurs when electron is being transferred from one electron carrier to another, starting from NADH and FADH2. A proton pump which is used to synthesize ATP is generated at the end.

This ETC process occurs in the cell membrane of prokaryotic cells due to the fact that they lack a membrane-bound Mitochondrion. ETC occurs in the inner membrane of the mitochondria called CRISTAE in eukaryotic cells.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint