Bacteria and viruses are the basis of the microcosm

According to K. Vez, all living beings are divided into several domains. There are three of them: bacteria, archaea and eukaryotes. Viruses are considered as an unranked category. The fact is that not all scientists attribute this group of beings to the living world. But most, as well as the creator of the hypothesis about the RNA world, tend to group viruses into a separate domain. And this, in spite of the fact that bacteria and viruses are the smallest among other creatures, and also quite simply arranged.

The question of the origin of viruses and bacteria remains open. There is not even an exact representation of which of these groups appeared earlier. It is logical to assume that viruses and bacteria must have a common ancestor and at least a unity of origin. Such judgments built the first theories. But a detailed study of these microorganisms led to the conclusion that the differences between viruses and bacteria are more significant than previously thought.

Difference between viruses and bacteria

The most important of these differences is the way of life, which bacteria and viruses have absolutely different. The first, despite the simplicity of their device, are independent beings. Even if they live inside the cell. How it is done, for example, chlamydia. Viruses outside the cell have no biological activity. They generally do not have any organs for elementary metabolism. A particle of all viruses consists of two elements. It is a genome (it is represented by one or two strands of ribonucleic acid) and a protein coat. Some have an additional capsid on top of the shell.

All viruses, depending on what ribonucleic acid they have, are divided into two large groups: RNA- and DNA-containing.

According to the form, there can be several variants of viruses.

• Icosahedrons.
• Fagi.
• Octahedra.
• Helical-shaped.

The size of the bacteria and viruses are quite different. If the sizes of the first are measured in units and hundreds of micrometers, then the largest virus is not more than 1300-1400 nanometers. Thus, the largest virus is smaller than the smallest bacterium.

The pathogenicity of viruses depends on the ability to penetrate certain cells.

While for the existence of bacteria, a combination of security against the aggression of the macroorganism and the ability to rapidly increase the number and formation of colonies is necessary. In other words: for bacteria it is most important to "conquer" a certain living space for existence.

Accordingly, both bacteria and viruses have different sensitivity to drugs aimed at their destruction. As antiviral drugs, interferons and their analogues are most effective. Antibiotics are used to control bacteria, which do not affect viruses.

The entire life cycle of viruses can be described in several stages. At first the particle penetrates into the cell. After that the genome of the virus is built into the genome of the cell. The latter begins to produce copies of the virus, and the cell organelles switch from their own metabolism to the creation of envelopes for these genomes. Then the viral particles leave the cell, and everything starts anew.

Viruses that are pathogenic to humans cause measles, smallpox, rubella, poliomyelitis, AIDS, upper respiratory tract catarrh and others. While bacteria are the culprits of whooping cough, diphtheria, typhoid, etc.