The next step in the nitrogen cycle is the assimilation of inorganic nitrogen in the type of ammonia into organic nitrogen-having compounds. Total organisms assimilate  ammonia  by two main reactions  catalyzed  by glutamate  dehydrogenase  and glutamine  synthetase  giving enhance to the amino acids glutamate (Glu)  and  glutamine  (Gln),  correspondingly.  The amino nitrogen in Glu and the amide nitrogen in Gln are then used in additional biosynthetic reactions to give increment to other compounds.