Answer:
Cellular membrane.
Step-by-step explanation:
In prokaryotes electron transport chain isIn prokaryotes electron transport chain is located in the cell membrane. ETC is defined as the series of complexes which helps in the transfer of electrons from electron donors to electron acceptors via reduction, and oxidation reaction couple the transfer of protons with electron transport across a member.
The primary function of the ETC is generated a transmembrane proton electrochemical gradient, such as oxidation, and reduction reaction.