In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. what is the advantage of such an electron transport chain? a scheme of cellular respiration. the initial compounds are 2h obtained from food via nadh and half of o2. 2h transforms into 2h plus and 2 electrons. these products have lower free energy than 2h and half of o2. electrons lose their free energy in the electron transport chain. this energy is used for atp synthesis. 2h plus and half of o2 lose their free energy and react with two electrons from the electron transport chain to create a water molecule that has less free energy than all the reactants. in cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. what is the advantage of such an electron transport chain?