Answer:
In the inner membrane of mitochondria
Explanation:
Electron transport chain is a composed of a series of complexes that facilitate the transfer of electrons form electron donors to the electrons acceptors. This electron transfer is coupled with the transfer of protons across the membrane which further creates the proton gradient. All these events occur in the inner membrane of mitochondria where the molecules that are involved in the electron transfer are located. These molecules are organic complexes viz.
The electron transport chain occurs in eukaryotes, both plant and animal cells.
