Both "depends upon the binding of that substance to a specific site on the membrane protein" and "depends upon movement of proteins from one side of the membrane to the other" are correct.
The saturation effect prevents statement 2 from being true.
The answer to your outstanding question is 3
Answer:
At the bottom you have the producers aka auto trophic livings (which use inorganic compounds to grow, produce energy, matter and so on..). These organisms would be plants, Cyrano bacteria, over all any organisms that do photosynthesis.
All matter is composed of protons, neutrons, and electrons. Therefore the answer is sodium.
