In order to begin to know the meaning of the term autotrophs, one must first discover its etymological origin. In this case, it can be said that it is a word that is a neologism formed from the sum of two words of Greek origin:
-The noun “autos”, which can be translated as “by itself”.
-The name “trophos”, which is synonymous with “food” or “nutrition”.
The adjective autotrophic is used to describe organisms that can take inorganic substances and transform them into the organic matter they need to survive.
Autotrophic organisms, therefore, can synthesize organic substances starting from other inorganic ones. This means that they do not need to feed on other living beings.
Said in a simplified way, autotrophic beings are those who are in charge of generating their own food. Their carbon source is carbon dioxide, while they produce energy from chemicals or light.
Among the autotrophic organisms we find plants and some bacteria. In the case of plants, these species resort to photosynthesis: the process that converts inorganic matter into organic matter through light. The light energy they receive from the sun’s rays is transformed into chemical energy, storing it in molecules of adenosine triphosphate (known as ATP). Then, ATP enables the synthesis of other more stable organic molecules.
According to DigoPaul, other autotrophic organisms appeal to chemosynthesis. These are bacteria that synthesize ATP by taking the energy released in reactions of inorganic compounds that have been reduced.
When talking about autotrophic nutrition, it is established that it is composed of three fundamental phases:
-Membrane passage. This is the phase in which the simple inorganic molecules (water, carbon dioxide and salts), through direct absorption, cross the cell membrane.
-Metabolism. When this second phase occurs, what takes place is a set of chemical reactions in the area of the cell cytoplasm. This leads to both the manufacture of own cellular matter and the obtaining of usable biochemical energy. Specifically, this second phase of autotrophic nutrition is divided in turn into three periods: photosynthesis, anabolism, which is also known as the construction phase; and catabolism, which is also called the destruction phase.
-Excretion. With this last phase the nutrition process ends. It consists basically in what is the elimination of the waste products of the previous process, of the metabolism. It is done through what is the cell membrane.
While plants and certain bacteria make their own food and are autotrophs, other organisms need to feed on other living things to obtain the substances that allow them to produce organic molecules of complexity. All animals, including humans, are heterotrophs.
These heterotrophs get energy by breaking down the molecules of the autotrophic organisms they ingest. When a carnivorous animal eats another animal, the energy also has its origin in an autotrophic being (ingested in a first stage by the eaten prey).