Final answer:
The chemiosmotic hypothesis claims that the free energy from redox reactions is used to pump hydrogen ions across a membrane to generate an electrochemical gradient and produce ATP through chemiosmosis.
Step-by-step explanation:
The chemiosmotic hypothesis claims that the free energy from redox reactions in the electron transport chain is used to pump hydrogen ions (protons) across a membrane, generating an electrochemical gradient. This gradient is then used to produce ATP through the process of chemiosmosis. The movement of hydrogen ions through ATP synthase, a membrane-bound enzyme complex, drives the synthesis of ATP from ADP and inorganic phosphate.