The combustion of glucose ultimately involves the transfer of electrons to oxygen (o2). in biological systems, this takes place without a large increase in temperature. which of the following statements about this process in biological systems is true? 1) coupled oxidation-reduction reactions occur with electrons being passed to intermediate electron carriers. 2) the process involves the transfer of 12 pairs of electrons to oxygen. 3) the transfer of electrons from intermediate electron carriers to molecular oxygen is catalyzed by the electron transport chain. 4) though the process is a controlled oxidation, some energy is lost.