Final answer:
Through the process of chemiosmosis, hydrogen ions pumped across the mitochondrial membrane generate ATP by flowing back through ATP synthase, driving the phosphorylation of ADP into ATP in a process called oxidative phosphorylation.
Step-by-step explanation:
The process in question is known as chemiosmosis, which is a critical part of cellular respiration occurring in the mitochondria. During this process, the pumping of hydrogen ions (protons) across the inner mitochondrial membrane sets up an electrochemical gradient. This gradient is then used to drive hydrogen ions back across the membrane through a protein complex called ATP synthase. This flow of protons through ATP synthase acts like a tiny generator turning, which in turn catalyzes the formation of ATP from ADP and inorganic phosphate. The resulting synthesis of ATP using this gradient is referred to as oxidative phosphorylation.
When examining the details of this mechanism, we find that the energy from electron transport chain reactions is utilized to pump hydrogen ions across the inner mitochondrial membrane, resulting in a higher concentration of these ions in the intermembrane space compared to the matrix. As these ions diffuse back across the membrane through ATP synthase, their potential energy is harnessed to phosphorylate ADP, thus producing ATP. It is this transfer of energy from the flow of hydrogen ions that ultimately generates the bulk of ATP during aerobic respiration.