Autotrophic, a kind of nutrition with carbon dioxide in the atmosphere or carbonate in the environment as carbon nutrition. This creature is called autotroph. Green plants and some bacteria are autotrophic. They can synthesize simple inorganic carbon dioxide or carbonate into complex organic matter to meet the needs of life activities.

According to the different energy needed in the process of assimilating carbon dioxide, it can be divided into light energy autotrophic type and chemical energy autotrophic type.

Photoautotrophic biological cells contain photosynthetic pigments, which can convert solar energy into chemical energy to meet the needs of life activities. In addition to green plants, there are a few bacteria (such as red sulfur bacteria and green sulfur bacteria), and cyanobacteria (such as ANABAENA and oscillatoria) are also photoautotrophic.

Chemotactic autotrophs gain energy by oxidizing some inorganic substances, such as nitrifying bacteria ammonia oxide (NH3), sulfiding bacteria sulfur oxide (S) or hydrogen sulfide (H2S).

Autotrophic organisms play an important role in carbon cycle, nitrogen cycle and sulfur cycle in nature.

heterotroph

Inorganic substances can't synthesize organic substances by themselves, but can only maintain metabolism by ingesting organic substances.