How Viruses Work: Virology

Virus diversity

Viruses are minute, non-living entities that duplicate themselves once inside the living host cells. All living organisms (animals, plants, fungi, and bacteria) have viruses that contaminate them. Usually, viruses are comprised of the coat (or capsid) that ensures its information molecule (RNA or DNA); these information molecules contain the blueprints for making more viruses. The viruses are profoundly various in their shape, size, genetic information, and infectivity. Viruses are all around us, on average a human body encounters billion virus particles consistently. Our intestinal, respiratory, and urogenital tract are reservoirs for many kinds of viruses, it is amazing that with such constant exposure, there is no impact of these organisms in human health. The host defense mechanism is quite strong to remove all these in normal conditions, while they cause numerous terrible diseases only when the person is immune-compromised. Despite viruses have a limited host range but sometimes they may jump the species barrier and causes fatal disease, Ongoing spread of swine influenza is an ideal example of such sort of spread.

The pandemic viruses, For example, influenza and severe acute respiratory syndrome (SARS), cause diseases that quickly spread to an enormous human population within no time, and appear to attract more scientific and public attention than do endemic viruses, which are constantly present in a specific population.

Virology as a discipline is simply 100 years old and the way it extended in this small period of time is widespread. To aggregate the new developing viruses in a particular group by indicating certain parameters was started in 1966 when the international committee on the taxonomy of viruses (ICTV) was formed with the aim to classify the viruses. The ICTV has adopted a standard for the description of the viruses. Name for genera, subfamilies, families, and orders must all be a single word, ending with the suffixes -virus -virinae, -viridae, and virales separately. In written utilization, the name should be capitalized and italicized.

Viruses are committed parasites which means theirs implies dependence on a living host system. This property of the virus made it an important tool to study cell functions and its biology. Adenovirus is an example of a DNA virus that enters the host nucleus however remains isolated from the host genome and simultaneously uses host cell machinery for its replication. Then again influenza is an RNA virus that conveys its own enzyme to replicate its genome while the viral proteins are synthesized by using the host cell machinery. Human immunodeficiency virus (HIV) is a retrovirus; it contains RNA as a genetic material however it converts into DNA after entering the host cell by an enzyme called reverse transcriptase. It additionally contains enzymes in its virion namely, integrase and viral protease which helps HIV during the maturation process inside the contaminated cells. The outer surface of HIV virion contains two surface glycoproteins called as gp120 and gp41 which helps in the attachment of the virus to the cell surface.