Final answer:
The transfer of electrons in the electron transport chain is typically accompanied by the transfer of protons.
Step-by-step explanation:
The transfer of electrons in the electron transport chain (ETC) is typically accompanied by the transfer of protons.
During the redox reactions of the ETC, high-energy electrons from electron carriers such as NADH and FADH2 are passed through a series of protein complexes and mobile electron carriers. As the electrons move through the ETC, protons are pumped across the inner mitochondrial membrane, creating a concentration gradient. This gradient is then used to drive the synthesis of ATP through a process called oxidative phosphorylation.