- Viruses are not living things. They have no cells, they cannot convert food into energy, and without a “host” they are just small clumps of chemicals.
- Viruses, on the contrary, are not dead - they have genes, they reproduce, and the processes of natural selection operate on them.
- Scientists struggled to detect viruses until 1892, when Russian microbiologist Dmitry Ivanovsky proved that tobacco plants were infected by creatures much smaller than bacteria. These creatures turned out to be a virus, specifically the tobacco mosaic virus.
- American biochemist Wendel Stanley isolated the above tobacco virus in its pure form as needle-shaped protein crystals, for which he received the Nobel Prize in 1946 in the field of chemistry.
- Some viruses insert their DNA into bacteria through hollow hairs, which are present on many bacteria.
- The word “virus” comes from a Latin word meaning “poison” or “dirty liquid,” which makes sense for a phenomenon that causes fevers and colds.
- In 1992, scientists traced the source of pneumonia that broke out in England - it turned out that it was a virus hiding inside an amoeba living in the towers of a cooling tower. It was so large that at first scientists mistook it for a bacterium.
- The so-called mimivirus is so named because it imitates the behavior and structure of a bacterium. Some experts believe that it is an intermediate link between bacteria and viruses, others are sure that it is a separate form of life. This virus characterized by the most voluminous and complex set of DNA among all viruses.
- The body of the mimivirus contains more than 900 genes that encode proteins that are not used in other viruses. Its genome is twice as large as that of other known viruses and even bacteria.
- There are even larger viruses called mamavirus. Their sizes are larger than those of some bacteria, and these viruses also have satellite viruses, which are called Sputnik.
- Amoebas are like sandboxes and soup kitchens for viruses - they absorb large objects within their reach and provide a source of nutrients for bacteria, which inside the amoeba exchange genes with other bacteria and viruses.
- Viruses can infect animals, plants, fungi, single-celled organisms and bacteria. Mamaviruses, together with their companions, also infect other viruses.
- We are all, perhaps, the result of the work of viruses, since a significant part of our genome contains “shards” and entire parts of viruses that penetrated into our ancestors millions of years ago and were “domesticated.”
- Many of the formations in our cells are at first glance useless, which is also explained by the fact that these are viruses that have safely taken root inside us at different stages of evolution.
- Most of the ancient viruses introduced into our genome do not exist in nature in our time. In 2005, French scientists began work on “resurrecting” one of these viruses.
- One of the viruses resurrected in this way, code-named Phoenix, turned out to be non-viable. Apparently, not everything is so simple.
- Some viral fragments in our genome are apparently responsible for the functioning of the autoimmune system and the development of cancer.
- We owe our very life to viruses - some of the proteins encoded by viral DNA in the mother’s body “correct” the body’s immune system so that it does not attack the embryo during development.
- We are all distant relatives on Earth. Scientists have reason to believe that a billion years ago one of the viruses entered a bacterial cell and from this a cell nucleus emerged, which subsequently led to the formation of a variety of flora and fauna, including you and me.
Viruses are chemical elements that have existed throughout life on earth. They are nonliving substances, they do not have cells, and viruses do not convert food into energy.
What does a virus consist of?
Viruses reach a size of 20 to 300 nm, which is half the size of the bacterium itself. They cannot even be seen with a regular microscope. The virus contains:
- core – genetic apparatus (DNA or RNA);
- protein shell (capsid);
- lipoprotein layer.
A fully formed virus is called a virion.
Each component of this virion has a specific role: the protein shell protects the virus from all kinds of damage, nucleic acid is responsible for genes, infectious properties and is responsible for the ability of viruses to adapt to bacteria, and enzymes help in reproduction.
Interesting facts about viruses that are worth knowing
Fact 1. Even though viruses are dead, they reproduce, they have genes and natural selection.
Fact 2. They introduce their DNA into healthy bacteria, thereby making them the causative agents of all kinds of diseases.
Fact 3. Mimivirus has the most complex genetic structure. This element can replicate the DNA of the affected bacterium and its behavior. Scientists believe that mimivirus is a kind of gap between a bacterium and a virus.
Fact 4. The largest in size are mamaviruses, which have their own satellite viruses. Interestingly, they are capable of infecting even other viruses in addition to living beings.
Fact 5. Scientists have also found out the following facts about viruses - it turns out that the human genome contains the remains of those infected cells that our ancestors had millions of years ago.
Fact 6. Human cells contain formations that are not necessary for life. It is believed that these are viruses that have taken root in the body and do not manifest themselves in any way.
Fact 7. In 2005, scientists from France tried to resurrect the ancient virus, but it remained lifeless, which further puzzled the researchers.
Fact 8. When an embryo forms inside a woman, the immune system recognizes the new embryo as something foreign. Thanks to the viral DNA, which encodes proteins, the fetus is not in danger from the immune system.
Fact 9. The most interesting fact about viruses is that life on earth was formed thanks to them. Due to penetration of bacteria malicious virus a cell was born that later formed life.
A particle that has some characteristics of living organisms, but is not one of them. They are similar to plants and animals in structure and function. Viruses do not and cannot replicate on their own, but rely on the host to produce energy, reproduce, and survive.
Although viruses are only 20-400 nanometers in diameter, they are the cause of many serious human diseases, including influenza, chickenpox and SARS (acute respiratory viral infection). Discover 7 interesting and educational facts about viruses.
1. Some viruses cause cancer
Some types of cancer are associated with cancer viruses. Burkitt's lymphoma, cervical cancer, liver cancer, T-cell leukemia, and Kaposi's sarcoma are examples of cancers that are associated with various types viral infections. However, most viruses do not cause cancer.
2. There is a "naked" virus
All viruses have a protein coating, or capsid, but some viruses, such as the influenza virus, are enclosed in an additional membrane called an envelope. Viruses without this extra membrane are called naked viruses. The presence or absence of an envelope is an important determining factor in how the virus interacts with the host membrane and enters and exits the cell after maturation.
Wrapped viruses can enter a cell by fusion with the host membrane to release their genetic material into the cell, whereas naked viruses must enter the cell through the host cell. Viruses with a membrane exit the cell through a process, while naked viruses must rupture the host cell to escape.
3. There are two types of viruses: DNA and RNA viruses
4. The virus can remain dormant for years
Viruses undergo a similar life cycle with several phases. The virus first attaches to the host through certain proteins on the surface of the cell. These proteins are usually receptors that vary depending on the type of virus targeting the cell. Once attached, the virus enters the cell by endocytosis or fusion. Host machinery is used to replicate the virus's DNA or RNA as well as essential proteins. After new viruses mature, the host is lysed so that new viruses can repeat the cycle.
An additional phase before replication, known as the lysogenic or dormant phase, occurs only in isolated cases. At this stage, the virus can remain inside the host for extended periods of time without causing any obvious changes in the cell. However, once activated, these viruses can immediately enter a lytic phase in which replication, maturation, and release occur. For example, HIV can remain dormant for 10 years.
5. Viruses infect plant, animal and bacterial cells
Viruses can infect bacterial and. The most common eukaryotic viruses are animal viruses, but viruses can also infect plants. Plant viruses usually need the help of insects or bacteria to penetrate. Once a plant is infected, the virus can cause several diseases that usually do not kill it, but cause deformities in growth and development.
The virus that infects is known as a phage. Bacteriophages follow the same life cycle, like eukaryotic viruses, and can cause diseases in bacteria, as well as destroy them through lysis. In fact, these viruses replicate so efficiently that entire colonies of bacteria can be destroyed in a short period of time. Bacteriophages are sometimes used in the diagnosis and treatment of bacterial infections such as E. coli and salmonella.
6. Some viruses use human proteins to infect cells
HIV and Ebola are examples of viruses that use human proteins to infect cells. The viral capsid contains both viral proteins and proteins from human cells. Human proteins help “camouflage” the virus from the immune system.
7. Retroviruses are used in cloning and gene therapy
A retrovirus is a type of virus that contains RNA and replicates its genome using an enzyme known as reverse transcriptase. This enzyme converts viral RNA into DNA, which can be integrated into the host DNA. The host then uses its own enzymes to translate the viral DNA into viral RNA needed for viral replication.
Retroviruses have the unique ability to enter humans. These special viruses have been used as important tools for scientific discovery. Scientists have developed a variety of techniques using retroviruses, including cloning, sequencing, and some gene therapy approaches.
Many diseases are associated with viruses. Here are some interesting facts about viruses.
Let us immediately note that viruses are not living organisms.
The word virus comes from a term translated as poison or contaminated liquid.
Without a carrier, viruses are simply clumps of chemical elements. Because they lack cells, viruses do not have the ability to convert any food into energy.
Viruses are capable of introducing their DNA into the body of bacteria through cavities in the hairs.
Among the extremely interesting facts about viruses, we note some funny ones. Araucana chickens are capable of laying unusual eggs - they are bluish or light green. And the reason for this is the retrovirus that these chickens are infected with. It inserts a gene into the host DNA that causes an increased concentration of biliverdin, a yolk pigment, in the egg shell. Interestingly, the quality of the eggs does not change; they do not become more harmful or beneficial when compared with ordinary eggs.
Scientists spent a lot of time determining the routes of infection for pneumonia, which spread in Britain in 1992. It turned out that the virus then found refuge inside amoebas that lived in cooling towers located on the roofs, used in air cooling systems. Because the virus had big sizes, then scientists initially mistook him for the pathogenic bacterium.
Large viruses are called mamaviruses. Their dimensions often exceed the size of even some bacteria. Such viruses have satellite viruses.
There is a widespread hypothesis that people are the product of viruses - a significant part of the human genome consists of “shards” and even entire parts of viruses that penetrated our ancestors. This happened a long time ago; over a long period of time, this “cocktail” of viruses was “domesticated.”
It is assumed that part of the viral fragments in our genome is responsible for the functioning of the autoimmune system and the prevention of cancer.
Without the participation of viruses, we could not be born - in order for the embryo not to be attacked by the immune system during its development, it is “corrected” by part of the proteins recoded by viral DNA directly in the mother’s body.
Nowadays, most of the ancient viruses that once penetrated our genome do not exist in nature. For research purposes, scientists in France began to “resurrect” some of these viruses in 2005.
But not everything turned out so easy. One of the newly “resurrected” viruses, called Phoenix, was revived non-viable.
One of the most dangerous virus-borne diseases is Ebola. The first signs are fever, sore throat, severe headache and muscle pain. This often coincides with cold or flu symptoms. Then nausea, diarrhea appear, damage to the kidneys and liver occurs, and sometimes external and also internal bleeding.
Interesting video. Secret files about viruses.
25.03.2016
Viruses are non-living substances in the form of chemical elements. They consist of a core containing DNA or RNA, a capsid, and a lipoprotein layer. Most diseases nowadays are of viral origin. Moreover, every year viruses change and mutate more and more. Therefore, knowing interesting facts about viruses is very very useful.
- Viruses are able to reproduce despite the fact that they are dead biological substances.
- Since viruses do not have cells, they cannot produce energy from the food they eat.
- Viruses reproduce due to their genetic makeup.
- Viruses are able to actively interact with bacteria. They insert their DNA into bacteria due to their microscopic size.
- In addition to bacteria, viruses can infect single-celled organisms, fungi, plants, and animals.
- Unlike all living organisms, viruses are not capable of synthesizing protein.
- Due to the fact that the virus is not a living organism, scientists have learned to synthesize them in laboratories.
- There is a theory that the human genome contains viral parts that were introduced into it in ancient times through our ancestors.
- Some viruses can cause cancer.
- In addition to living organisms, viruses can also infect other viral particles.
- Mimiviruses are an element similar to the average variant between a virus and a bacterium, which is capable of repeating the DNA and behavior of the bacterium itself.
- Mamaviruses are extremely large viruses.
- Viruses, unlike bacteria, are not able to reproduce in artificially created nutrient media. Their reproduction is possible only in a living organism. Therefore, viral cultures are grown in embryos or inside experimental animals.
- Reproduction of the virus is most often associated with a cell
- The routes of transmission and infection by viruses are varied: airborne, contact, sexual, alimentary, through biological fluids.
- There are viruses that live for a long time in the host cells and do not cause disease.
- It has been proven that the existence of one virus in the cells of the body prevents the harmful effects of another virus. In such cases, the reproduction of one of the viral substances is suppressed by the production of a special protein. This phenomenon is called interference. Subsequently, an antiviral drug, interferon, was developed on its basis.
- For the diagnosis of viral diseases, specific serological reactions are priority.
Viruses pose a particular threat to living organisms. Considering that more and more new viruses are being synthesized in the world and their DNA is capable of mutation, the development of antiviral drugs remains very relevant.