A huge variety of living beings live on Earth. For the convenience of their study, researchers classify all organisms according to various characteristics. According to the type of nutrition, all living things are divided into two large groups - autotrophs and heterotrophs. In addition, a group of mixotrophs stands out - these are organisms adapted to both types of nutrition. In this article, we will analyze the features of the life of the two main groups and find out how autotrophs differ from heterotrophs.
Autotrophs are organisms that independently synthesize organic substances from inorganic ones. In this group are some types of bacteria and almost all organisms belonging to the plant kingdom. In the course of their life, autotrophs utilize various inorganic substances coming from outside (carbon dioxide, nitrogen, hydrogen sulfide, iron, and others), using them in the synthesis of complex organic compounds (mainly carbohydrates and proteins).
Heterotrophic organisms feed on ready-made organic substances, they are not able to synthesize themon one's own. This group includes fungi, animals (including humans), some bacteria, and even some plants (some parasitic species).
As we can see, the main difference between heterotrophs and autotrophs is the chemical nature of the nutrients they need. The essence of the processes of their nutrition also differs. Autotrophic organisms expend energy when converting inorganic substances into organic ones, heterotrophs do not expend energy when eating. Autotrophs and heterotrophs are divided into two more groups depending on the energy source used (in the first case) and on the food substrate used by microorganisms of the second type.
Among autotrophs, photoautotrophic and chemoautotrophic organisms are distinguished. Photoautotrophs use the energy of sunlight to carry out transformations. It is important to note that in the organisms of this group a specific process occurs - photosynthesis (or a process of a similar type). Carbon dioxide will turn into various organic compounds. Chemoautotrophs use energy obtained from other chemical reactions. Various bacteria belong to this group.
Heterotrophic microorganisms are divided into metatrophs and paratrophs. Metatrophs use dead organisms as a substrate for organic compounds, while paratrophs use living ones.
Autotrophs and heterotrophs occupy certain positions in the food chain. Autotrophs are always producers - they createorganic substances that later pass through the entire chain. Heterotrophs become consumers of various orders (as a rule, animals are in this category) and decomposers (fungi, microorganisms). In other words, autotrophs and heterotrophs form trophic relationships with each other. This is of paramount importance for the ecological situation in the world, since it is due to trophic links that the cycle of various substances in nature is carried out.
