Viruses are tiny beings, measuring about 0.1 µm in diameter, with dimensions only observable under an electron microscope. They basically consist of nucleic acid, which can be DNA or RNA, surrounded by a protein shell called capsid, which in addition to protecting genetic material, chemically combines with cell membrane receptors parasitized.
These beings are acellular, not having organs that perform the complex biochemical synthesis. They only express vital activities: reproduction and propagation, inside a host cell. Therefore, they are considered obligate intracellular parasites.
Mind Map: Virus
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When the parasitic relationship is established, the viral genetic material takes over the cell, turning almost exclusively the metabolism to originate hundreds of new viruses in question of minutes.
Some are classified as enveloped, having a lipoprotein envelope coming from the host cell membrane. In this classification, the Human Immunodeficiency virus -HIV stands out.
Generally, the term virus refers to the installation / infection process in eukaryotic organisms (which have genetic material surrounded by nuclear membrane) while the term bacteriophage is designated to viruses that install themselves in prokaryotes (organisms that do not have a nuclear membrane involving the cell's genetic material: bacteria).
Currently, approximately 3,600 species have been identified, which can infect bacteria, plants and animals, as well as establish themselves and cause human illnesses. Each disease with particularities regarding the mode of transmission, characteristics of the infection and prophylactic measures.
The viral diseases that most affect the human body are the following: Flu, Chickenpox or Chickenpox, Mumps, Dengue, Yellow Fever, Hepatitis, Rubella, Measles, Smallpox, Herpes Simplex and Rabies.
* Mental map By M. Vanessa Sardinha dos Santos
by Krukemberghe
Graduated in Biology
