The following process that is illustrated by the downward arrows from the atmosphere that show the conversion of nitrogen gas into usable forms available to producers is "Nitrogen Fixation"
Nitrogen Fixation refers to the process which leads to the conversion of nitrogen in the air into ammonia (NH3) or other related nitrogenous compounds in the soil. This process is very essential because the biosynthesis of all nitrogen-containing organic compounds is as a result of the inorganic nitrogen compounds.
Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells.
The solution is hypertonic because the amount of solute(s) is higher outside of the cell than it is inside the cell, so the solvent (e.g. water) would move from the cell to the solution in order to obtain equilibrium between the two.