Viruses Research Paper

Viruses are unique and completely different to all the other micro-organisms. They are not included in the Five Kingdom classification system. They are genetic entities classified as to exist between living and non-living states.They are the smallest type of microbe and sometimes described as an intracellular parasites.

Viruses have simple structures that differ in size and shape. They do not have a nucleus, instead viruses have one or two strands of dna and rna to protect it. This coat is called a capsin, some viruses have another protective layer called envelope.

Viruses needs host cells to infect so it can reproduce. Viruses exist as a capsid or protein coat and sometimes enclosed within a membrane when not attached to its host. The capsid

Viruses which can have either RNA or DNA genomes have the highest per base pair per generation mutation rates. DNA viruses mutation rates is between 10−6 to 10−8 mutations per base per generation, and RNA viruses' mutation rate is between 10−3 to 10−5 per base per generation.

Common Viral Sequence of Infection The virus needs to enter a host, then tightly attach itself to the host cell. Tight attachment of the viral particle to receptor enables fusion with the cell membrane. This will allow the virus to take control of its host cell and add its viral content.

Viruses may remain inactive inside its host cells for a long time. This stage is known as the lysogenic phase. At this phase, no obvious change will occur in the host cell. It enters a lytic phase or active phase when a dormant virus is stimulated. At this phase host cell burst out as new viruses are formed. The virus will then infect other cells and do the process again. Reverse transcriptase is an enzyme then reads the sequence of viral RNA nucleic acids and transcribes the sequence into a complementary DNA sequence. The viral genome can not be incorporated into the host cell and will not be able to reproduce without reverse

This results in a variety of subtle molecular differences in surface enzymes and coat. Viruses produced from a single infected cell will not be all alike.

The virus has a unique enzyme called integrase. This enzyme incorporates the viral DNA to that of its host and once the viral RNA has been reverse-transcribed into a strand of DNA. The new DNA code can now be integrated as the new DNA code of that cell. The integrated DNA is called a provirus. Before these enzymes become functional, they must be cut from the long DNA code.

As long as the provirus is not turned-on, nothing happens to the viral DNA; If it is activated, transcription of the viral DNA will begin. This will result in the production of multiple copies of the viral RNA. Viral protease cuts the long code to produce its individual enzyme components and then will be packaged as new viruses. Then released into the system. These enzyme will then bind to the receptors on other cells facilitating continued infection.

Common Pathogenic Viruses Found in