Final answer:
Nitrogenase activity in anaerobic bacteria and ATP synthase mutants experiments demonstrated that ATP can be generated without the proton-motive force.
Step-by-step explanation:
The experiment that demonstrated ATP can be generated without the proton-motive force is called nitrogenase activity in anaerobic bacteria. Nitrogenase is an enzyme that converts atmospheric nitrogen into ammonia, a process known as nitrogen fixation.
This enzyme requires ATP to function properly, but it does not rely on the proton-motive force to generate ATP. Instead, it uses other sources of energy such as ferredoxin or pyruvate.
Another experiment that showed ATP synthesis without the proton-motive force was conducted using ATP synthase mutants. These mutants were unable to generate the proton gradient required for ATP synthesis, but ATP production was still observed. This indicated that ATP can be generated through alternative mechanisms.
Overall, these experiments provide evidence that ATP synthesis can occur without the proton-motive force, highlighting the versatility of cellular energy production.