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What is Prokaryotic Cell?

Meaning of Prokaryotic Cell

The word prokaryote is of Greek origin and means “anterior nucleus” or “before having a nucleus”. This meaning gives the impression that it is a primitive structure, and that is exactly what these organisms are about.

Compared to eukaryotes, prokaryotic cells are simpler, leading to the belief that they are more primitive elements in evolutionary history. Therefore, it is believed that the first cell was that of a prokaryotic being.

This group of organisms is basically made up of bacteria. Their cells are not organized into tissues, that is, they are unicellular organisms, which may or may not form colonies.

The composition of this cell group has few membranes, in general, the only one present is the one that delimits the cell.

The prokaryotic cell is characterized by the absence of well-known and common membranous organelles, such as mitochondria, chloroplast, Golgi complex, etc. It has a plasma membrane, cytoplasm, free and non-compartmentalized genetic material, and ribosomes.

The plasma membrane delimits the organism and has its typical function of controlling the entry and exit of molecules from the cell. The cell wall is commonly found in prokaryotes, composed of protein-bound carbohydrates called peptide-glycans.

Depending on their thickness and complexity, organisms can be divided into two groups of bacteria: gram positive and gram negative.

In short, it can be said that those with a thicker cell wall are gram positive and those with a thinner cell wall are gram negative.

The genetic material is composed of chromosomes and plasmids and is the main responsible for genetic inheritance. The former is analogous to a cell’s command center, which “manages” the cell’s internal processes.

It is diffuse in the cytoplasm and is present in a region called the nucleoid. The other structure, which is also made up of DNA, is an extra circular structure of chromosomal DNA responsible for the inheritance of some important traits, such as resistance to certain antibiotics.

A structure that may or may not be present in bacteria is the sexual pilus or fimbria. This appendix refers to the transfer of the plasmid to another bacterium to confer some advantage of the ability to produce a certain protein.

A curious fact is that this combination of structures, plasmids and sexual fimbriae, is of vital importance for the cell itself. What is beyond common sense is that the knowledge of this has brought enormous advances for humanity.

It is thanks to the knowledge of the structure and its functioning that the technology is capable of making a culture of bacteria produce insulin of human origin.

This occurs by inserting a human DNA sequence responsible for the production of this substance into the plasmid of a bacterium. It then reproduces and transmits that genetic portion to the rest of the crop, causing production.

There are some other specialized structures that may be present in these cells.

Cilia and flagella are structures that originate from the centriole and have a function related to locomotion. The capsule is a structure external to the plasmatic membrane, present in some pathogenic bacteria that act to protect the organism, often making it difficult for the immune system to fight.

The importance of these beings is enormous and also very varied, and their performance is vital for life and also for technological development. This is because decaying beings and nitrogen fixers have prokaryotic cells.

This means that the decomposition of organic matter and its return to nature is carried out by these organisms. Furthermore, the role of nitrogen fixers is even more important.

This is because this element, in the form in which it is available in nature, cannot be absorbed by producers to be transmitted through the food web. It is precisely the nitrogen fixers that allow the use of the chemical element.

In terms of technology, the first and several current studies related to biotechnology were carried out with prokaryotic cells because they are simpler.

So much so that one of the best known and most studied cells in the world is a species of bacteria present in the intestinal tract, Escherichia coli. In other words, the existence of prokaryotes is indispensable for life as we know it today.

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