Heterotrophic beings

Heterotrophic beings. (from the Greek hetero, other, unequal, different and trophic, which feeds), in contrast to autotrophic organisms, are those that must be fed with organic substances synthesized by other organisms, either autotrophic or heterotrophic in turn. Among heterotrophic organisms are a multitude of bacteria and predominantly animals.

Summary

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• 1 Classification
• 2 Nutrition
• 3 Heterotrophic cells
• 4 Autotrophic cells
• 5 Differences between autotrophic and heterotrophic cells
  • 1 Origin of heterotrophic or autotrophic cells
• 6 External links
• 7 Sources

Classification

A heterotrophic organism is one that depends on another, that is; from an external source of organic molecules, in terms of their energy. Depending on the origin of the energy used by heterotrophic organisms, they can be divided into:

1. Photorganotrophs: these organisms fix the energy of light. They constitute a very small group of organisms that comprise the purple bacteria and pseudomonal family. They only perform energy synthesis in the presence of light and in oxygen-deficient media
2. Chemo-organotrophs: they use chemical energy extracted directly from organic matter. To this group belong all the members of the animal kingdom, all of the fungal kingdom, a large part of the moneras and of the archaeobacteria. Autotrophs and heterotrophs need each other to exist.

Nutrition

Nutrition is the process by which food undergoes a series of transformations within living things to become useful nutrients to the body for its growth, development and maintenance.

There are two types of nutrition in living beings: Autotrophic Nutrition and Heterotrophic Nutrition. Autotrophic nutrition is that carried out by green plants with chlorophyll, where the plant makes its own food ( organic substances ) from carbon dioxide in the air and the water it absorbs from the environment (inorganic substances) through a series of chemical reactions ( cellular metabolism ), where light is indispensable in some of them, called photosynthesis as a whole.

Heterotrophic nutrition is that carried out by the rest of living beings that do not carry out photosynthesis and in which we require consuming food (organic matter).

Heterotrophic cells

They are the ones that need to get substances from the environment to extract the energy. They are called heterotrophic cells, because they cannot make their own food and need producers to obtain energy through the food they make to continue living.

Heterotrophic cells use the organic matter they obtain from the environment to obtain energy, through catabolism reactions. The most widely used molecule for energy is glucose. This is subjected to various chemical oxidation reactions inside the cell, until it is completely degraded and transformed into carbon dioxide (CO ₂ ).

Autotrophic cells

Autotrophic cells are those that do not need to obtain substances from the medium to extract energy, since they can transform light energy into chemical energy (ATP). This process of anabolism takes place in chloroplasts. The energy thus obtained is used to synthesize organic substances from inorganic substances (water, carbon dioxide and mineral salts). This is the process called photosynthesis.

A part of the organic compounds synthesized by autotrophic cells are used by them to obtain energy through catabolism, and another part is used for anabolism, the synthesis of more complex substances that are components of cellular structures.

Differences between autotrophic and heterotrophic cells

Heterotrophs do not have chloroplasts and autotrophs do, which is why autotrophs can manufacture their own food and heterotrophic cells, lacking chloroplasts, cannot elaborate it, necessarily requiring autotrophic cells, since chloroplasts are indispensable organs to manufacture their own food by the photosynthesis process.

Origin of heterotrophic or autotrophic cells

Before the appearance of life, simple organic substances could have existed in a kind of primitive broth.

For Oparin, the first cells that arose by evolution of the coacervates had to be prokaryotes (cells without nuclei) and heterotrophs, that is, they fed on the molecules of the primitive soup; As soon as these began to become scarce, given the rapid proliferation of cells, competition for food arose and those with the greatest ability to adapt survived.

The first cell to emerge was relatively simple, surely a heterotrophic prokaryote. It is assumed that this cell was preceded by aggregates of RNA, DNA, and proteins, enveloped by lipid bilayers. These aggregates continued evolution and gave rise to the first cells.

For this reason we can deduce that the type of cell that first originated was that of the heterotrophic type, since they used organic substances as food and did not possess the capacity (like current autotrophs) to feed on inorganic substances.

It is clear that for Oparin the first cells to emerge were heterotrophs alleging that the Earth had just formed and when the first organisms had not yet appeared, the atmosphere was very different from the current one, according to Oparin this primitive atmosphere lacked oxygen but there were substances like : hydrogen , methane and ammonia; that some cells used these to feed; that is why it can be said that the first cells were anaerobic heterotrophs (since they were nourished by taking the substances from the medium and lived in the absence of 0 ₂ ).

But these cells (heterotrophs) adapted to this form of feeding to these extreme initial conditions; until due to the increasingly pressing absence of nutrients in the medium, some cells began to manufacture their own nutrient molecules using sunlight and CO ₂ present in the atmosphere. In this way, autotrophic cells appeared and with them the mechanism of photosynthesis; cells that did not adapt to the new nutrition system disappeared over time. After going through this process, the autotrophic cells evolved over the years.