Virus – What is a Virus?
You’ve been hearing about the word virus every day. But do you know what a virus is? Now is time to drop that vague definition and learn what Viruses really are.
Before we proceed with our definition of a virus, it should be noted that they are one big class of microorganisms.
[tds_warning]A virus is a small collection of genetic code, either DNA or RNA, surrounded by a protein coat. A virus cannot replicate alone. Viruses must infect cells and use components of the host cell to make copies of themselves. Often, they kill the host cell in the process, and cause damage to the host organism.
Viruses are so small that they are measured in millionths of a millimeter (nanometers). For example, it would take over 200,000 influenza virus particles to just cover the dot at the end of that sentence.[/tds_warning]
VIRUSES ARE NOT TRULY LIVING CREATURE
Viruses do not feed, breathe, remain motionless, and are unable to reproduce on their own, so they are not truly living things. In fact, in order to reproduce, they must necessarily infect a living cell and force it to make its own offspring – new viruses.
The infected cell dies after it has completed its task. It releases many virus particles, which in turn infect other cells.
What are viruses made of?
Viruses have a very simple organization. Their genetic program (made up of DNA, as in all living things, or, in some cases, RNA) is protected in a capsid made of proteins called a capsid.
Sometimes the capsid is surrounded by an envelope of lipids (this is the case, for example, of the AIDS virus): in this case, the virus is said to be enveloped.
Further reading on Viruses
Tag:Biology, Human Biology, Microorganisms, Virus