What is a Viral Disease?

A virus is an extremely small submicroscopic viral agent that replicates within an organisms’ living cells. Virtually all viruses infect all living forms, including plants and animals to bacteria, in addition to archaea, which includes fungi and other fungi. A virus may jump from one organism to another by borrowing DNA or using other proteinases called transposons, or sometimes it may be part of a larger group of viruses that use gene expression to multiply.

The envelope of a virus is constructed with ribosomes, as well as transcription units and other elements that are unique to each virus type. The envelope also serves as the major entrance gateway for the viral particles that make up the virus. At the other end of this extremely small envelope is the cellular destination, where the virus produces a functional protein, attaches itself to a host cell, and uses that cell as a shield until it either slips away completely, or triggers a reaction that destroys the host cell. In order for a virus to enter a host cell, however, the virus must have a functional envelope, or outer protein cover.

There are two types of viral envelopes: linear and circular. A virus that utilizes a linear envelope is a simplex virus – a kind of single-celled organism that duplicates by using a pair of paired chromosomes. A virus with a circular envelope, on the other hand, is an envelop Virus. A circular envelope replicates via a process called intracellular reproduction (ICR).

There are several different ways a virus can invade a host cell. One way is through a physical intrusion, such as when a virus engulfs a uninfected cell near the surface. Another way is through an entry of a viral message into the host’s genetic code, which is then passed on to the rest of the host’s cells. Some viruses can also latch onto and engulf the host cell directly through a lymph or blood vessel.

The major difference between these types of viruses and the retroviruses that destroyed cells centuries ago is the virus’ envelope. The envelope of a retrovirus is made up of three main protein components – a protein domain (protein binding), a capsid (protein covering), and a toxin (protein causing illness). Unlike bacteria, which has only one protein domain and uses a tail to hide its bacterial infecting DNA, the protein domains of a retrovirus include multiple copies of themselves. This allows the retrovirus to lay down its own protein coat over the bacterial envelopes of the host cell, starting a chain reaction that leads to a complete enveloping of the cell and the destruction of its DNA.

For viruses to survive and replicate, they need a method of copying themselves into DNA. The method they use is called transcription, and the DNA they copy themselves into is known as a template. The template is then used in creating the full set of necessary amino acids needed to make the viral proteins, and these full sets are then passed on to the next generation of virus.