Answer :
well the energy is stored in NADH and FADH2 during the krebs cycle and convert it to chemical bond energy in the form of ATP. In Eukaryotas, this reaction takes place on the inner mitochondrial membrane.
It depends on if you are talking about bacteria, archaea, or eukaryotes. In bacteria and archaea, there are no membrane-enclosed compartments, so the electron transport chain is on the cellular membrane. In eukaryotes, the electron transport chain components are on the mitochondrial membrane.