What is autotroph?

We explain what an autotrophic being and a heterotrophic being are. What this classification of living beings implies. Examples of autotrophs.

What is autotroph?

When we talk about autotrophic organisms or autotrophic nutrition we always refer to a classification of living beings based on their ability to obtain energy. 

This classification distinguishes them into two groups:

Heterotrophs. Those that must consume organic matter from other living beings.

Autotrophs. Those capable of managing the production of their own energy, taking advantage of environmental elements.

In this way, an autotrophic being is one that does not need other living beings to nourish itself, but synthesizes everything it needs for its metabolism from inorganic substances. Put more simply: they are beings that make their own food.

There are two major autotrophic methods of nutrition: photosynthetic and chemiosynthetic. The former take advantage of water and the energy of sunlight to break down the carbon dioxide (CO 2 ) molecule from the surrounding air, and thus obtain energy. 

The latter, on the other hand, do so by oxidizing inorganic chemicals such as sulfur dioxide or various iron-rich compounds. The former are known as photolithotrophic beings, and the latter as chemolithotrophic beings.

Obviously, autotrophic beings represent the first step in all trophic cycles or food chains, since they constitute the producing link, that is, the one that takes the raw material directly from the environment. And they are the ones who provide organic matter to heterotrophic beings (whether they are herbivores, predators or even decomposers).

Examples of autotrophic beings

Plants. From fruit trees, vines, shrubs, lawns, and tall tall trees, to the greenish moss that lines rocks near rivers, all these living things make their nutrients through photosynthesis.

The seaweed. Algae of varying size and complexity, as well as the microscopic phytoplankton found in abundance in the seas, are autotrophic life forms typical of seas, lakes, and large bodies of water.

Cyanobacteria. Previously known as blue-green algae, they are prokaryotic living beings (with cells without a nucleus), capable of carrying out photosynthesis and fixing environmental nitrogen (N 2 ), reducing it to a useful molecule at the cellular level, such as ammonium (NH 4 + ).

Anaerobic bacteria. Some of the bacteria that make up the intestinal flora of humans are good examples of autotrophic beings. They take care of breaking down ingested organic matter and triggering chemical reactions that break their structures and simplify the digestive process, while extracting energy to sustain their own metabolisms.