VIRUS

According to the biologist, the virus is the transition between the organisms living beings and dead objects. Told of the virus because it has characteristics of living beings, for example, have DNA (deoksiribonukleat acid) and can proliferate on living cells. Have discrete objects such as dead and do not have the protoplasm can dikristalkan. The inventors of viruses, among others, D. Iwanoski (1892) in tobacco plants, followed M. Beijerinck (1898), Loffern and Frooch (1897) find and separate the virus causes foot and mouth disease (food and mouth diseases), Reed (1900) to find the virus causes yellow (yellow fever), Twort and Herelle (1917) inventors Bakteriofage, Wendell M. Stanley (1935) successfully mengkristalkan on tobacco mosaic virus. Knowledge about the virus continues to develop until birth biological sciences branch of study called virus virology.

1. Virus characteristics
Ultra-microscopic size
Sejati parasites / parasite obligat
Oval-shaped, rounded, the stem, the letter T, spindle
Kapsid composed of proteins that contain DNA or RNA
Can dikristalkan
Activities must be beings living in cell

2. Virus Structure
To know the structure of the virus generally we use bakteriofage (T virus), the structure consists of:
a. Head
Head of the virus contains DNA, and the veiled kapsid outside. One unit of protein prepared kapsid called kapsomer.
b. Kapsid
Kapsid jacket is in the form of protein. Kapsid consists of kapsomer. Kapsid can also consist of a protein monomer consists of a chain polipeptida. Kapsid function to the form of the virus as well as protecting the virus from the environment of harmful viruses.
c. The contents of the body
The top of the acid content in which the core, ie, DNA or RNA alone. The contents referred to as the virion. DNA or RNA is the genetic material that contains the code of the nature of the virus. Based on the contents of dikandungnya, the virus can be divided into viral DNA (T virus, variola virus) and RNA viruses (influenza virus, HIV, H5N1). In addition, in the content of the virus, there are several enzyme.
d. Tails
Ekor virus is a tool to patch the inangnya. Tails, the virus consists of tubus bersumbat equipped yarn or fiber. Viruses menginfeksi cells eukariotik not have any tails.

3. Virus Reproduction
How to reproduce the virus known as proliferation, which consists of:
a. Litik cycle (cycle litic)
1. Adsorbsi phase (phase penempelan)
Marked with the virus melekatnya tails on bacterial cells. After removing the virus stick to lisoenzim enzyme (not enzyme) form so that the hole in the wall of the bacteria to enter the nucleus acid virus.
2. Injection phase (insert acid core)
After the holes form in the bacterial cell so the virus will enter the core acid (DNA) to cells in the body of the bacteria. So kapsid virus remain outside the bacterial cell and work again.
3. Phase Synthesis (establishment)
DNA virus akan affect bacterial DNA for mereplikasi parts virus, so terbentuklah parts of the virus. In bacterial cells that are not powerless and that disintesis virus protein used as kapsid virus, the virus in the DNA.
4. Phase Asemblin (assembly)
Parts of the virus that has been established, the bacteria will be built by a perfect virus. The amount of virus that around 100-200 units in a single cycle litik.
5. Phase Litik (wet nurse cell rupture)
When assembly is complete, then the virus will destroy the cell walls of bacteria with the enzyme lisoenzim, eventually the virus will look for a new wet nurse.
b. Lisogenik cycle (cycle lisogenic)
1. Merging phase
Penetrate between two objects in the bacterial DNA to viral DNA must be cut off bacterial DNA, and DNA viruses penetrate between two objects in the yarn between the DNA of bacteria is lost. In other words, the bacteria are in the DNA genetic material of viruses.
2. Phase division
After DNA virus does not penetrate between two objects called active profag. Then bacterial DNA cleavage mereplikasi to do.
3. Phase Synthesis
DNA synthesis for the virus to form part of the viirus
4. Assembly phase
After the virus form part of the virus, and then into the DNA will form a new virus
5. Phase Litik
After assembly is complete there lisis bacterial cells. Virus released from the wet nurse wet nurse akan explore new

4. Virus classification
According to the classification of Bergey, virus to include in the divisio Protophyta, class Mikrotatobiotes and ordo Virales (Virus). In 1976 the ICTV (International Commite on Taxonomy of Virus) virus that publish classified structure and composition of the body, which is based on the sour womb. Basically the virus be on the two groups, namely the virus DNA and RNA viruses.
a. DNA viruses have several relatives:
1. Family Parvoviridae, such as the genus Parvovirus
2. Family Papovaviridae such as the genus Aviadenovirus
3. Family Adenoviridae, such as the genus Mastadenovirus
4. Herpesviridae family, such as the genus Herpesvirus
5. Iridoviridae family as the genus Iridovirus
6. Poxviridae family, such as the genus Orthopoxvirus
b. RNA viruses have several families:
1. Picornaviridae family, such as the genus Enterivirus
2. Family Reoviridae, such as the genus Reovirus
3. Such as family Togaviridae genus Alphavirus
4. Family Paramyvoviridae such as the genus Pneumovirus
5. Orthomyxoviridae family, such as the genus Influensavirus
6. Retroviridae family as the genus Leukovirus
7. Rhabdoviridae family such as the genus Lyssavirus
8. Arenaviridae family as the genus Arenavirus

5. Role of Virus in Human Life
a. The virus, which benefits, to work:
1. Make antitoxin
2. Weaken the bacteria
3. Producing vaccine
4. Pathogenic attack
b. Harmful viruses, diseases caused by viruses, among others:
1. On vegetation
Mozaik on leaf tobacco Tobacco Mozaic Virus
Mozaik on potato Potato Virus Mozaic
2. Mozaik tomato on Tomato Aucuba Mozaic Virus
Floem damage on citrus Citrus vein Phloem Degeneration
3. Animals on
Tetelo poultry on New Castle Disease Virus
Vicinia the cow pox virus
Blue tongue in sheep Orbivirus
Gland tumor susu monkey Monkey Mammary Tumor Virus
4. On Human
Influenzavirus influenza
AIDS Retrovirus
SARS Coronavirus
Bird flu Avianvirus

6. Self Defense Against Virus Attacks
The ability of viruses to cause a disease called virulensi. Virulensi virus is determined by:
a. presence and activity on the surface of the wet nurse reseptor that allows the virus to adhere
b. ability of the virus menginfeksi cells
c. speed of virus replication in cell wet nurse
d. wet nurse in the ability of cells to withstand the attack of the virus
Most of the virus into the human body through the mouth and nose, a skin wound. If there is a virus that comes in, the body will maintain the cells with the cell fagosit, antibody, and Interferon (typical protein)