Macro: 1 heterotrophs is the animal we are talking about now, including people. Nitrogen source is organic matter: 20 kinds of α -amino acids. Ruminants are a little special, and they can use non-protein nitrogen (inorganic substances): urea, ammonia, (and possibly others). Autotrophic organisms are plants, which use inorganic substances and absorb them in the form of ions, which is their nitrogen source (some plants can also eat meat, which is also considered as using organic substances).
Microscopic examination: 1 heterotrophs: heterotrophs obtained organic substances by predation, digested and absorbed these small molecules and synthesized them into its own substances, such as polysaccharides, protein, nucleic acids and lipids. This is the assimilation of heterotrophs (an ordinary animal). So its nitrogen source comes from organic matter. Autotrophic organism: refers to an organism that lives and reproduces only with inorganic compounds as nutrients. So its nitrogen source is inorganic.