The pair of word that best describes the analogy: Prescription : physician is:
-Ruling : Judge. Knowing that a physician is a person qualified to practice medicine and that he is the official person who can provide a prescription (an order that is written by a physician). In the same sense, a judge is public official appointed to make a ruling (authoritative decision).
Materials move within the cell 's cytosol by diffusion, and certain materials move through the plasma membrane by diffusion. Diffusion expends no energy. On the contrary, concentration gradients are a form of potential energy, dissipated as the gradient is eliminated.