Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Question: Metabolism is controlled by regulation of what? Answer: enzyme activity
8.5 Regulation of enzyme activity helps control metabolism.

Question: Pressure and ________ are directly proportional at a constant volume? Answer: temperature
Pressure and temperature are directly proportional at a constant volume.

Question: The mechanical advantage of a machine is related to how it changes what? Answer: force
The mechanical advantage of a machine is related to how it changes force. Explain this relationship.