Virus Discovery History
Research on the virus begins with the study of mosaic disease that inhibits the growth of tobacco plants and make the plant leaves have spots.
The virus has the following characteristics:
1. Viruses are aseluler (do not have a cell)
2. Virus-sized very small, much smaller than bacteria, which ranged between 20 mμ - 300mμ
3. The virus has only one kind of nucleic acid (RNA or DNA)
4. Viruses are generally in the form of such a crystal (crystal) and shape very greatly.
1. Viruses are aseluler (do not have a cell)
2. Virus-sized very small, much smaller than bacteria, which ranged between 20 mμ - 300mμ
3. The virus has only one kind of nucleic acid (RNA or DNA)
4. Viruses are generally in the form of such a crystal (crystal) and shape very greatly.
5. Virus body consists of: head, skin (coat or capsid), the contents of the body, and tail fibers.
6. Virus has a layer of proteins called capsid
7. Viruses can only multiply in other living cells. As living cells in bacteria, animals, plants, and living cells in humans.
8. Viruses can not divide.
9. Viruses can not be precipitated by centrifugation usual, but can be crystallized
Virus Forms
Body Shape Virus is Stem, round, polihindris, and like the letter T.
Virus Reproduction
Viruses can only multiply in living cells or tissues. Therefore, the virus infects a bacteria cell, animal cell, or plant cells to reproduce. Mode of reproduction is called a virus proliferation or replication.
In Bakteriofage reproduction can be divided into two kinds, namely lytic cycle and lysogenic cycle. In the lytic cycle, the virus will destroy the stem cells after successful reproduction, whereas in the lysogenic cycle, the virus does not destroy bacterial cells but the viral DNA integrated into bacterial cells, so that if the bacteria divide or multiply split virus, too.
In principle, how the proliferation of viruses in animals and in plants similar to that which took place on bakteriofage, namely via the phase of adsorption, synthesis, and lysis.
a. Lytic infection / lytic cycle
Lytic cycle through the following phases:
1. Phase adsorption and infection
With the tip of its tail, phage attached to or infecting certain parts of the bacterial cell wall, the area was called the receptor (receptor site: receptor spots). This area is typical for a specific phage, and phages of other species can not be attached in place. Viruses attacking the bacteria do not have the enzymes for metabolism, but rnemiliki lysozyme that function damage or pierce the cell walls of bacteria.
After the wall sei bacteria hydrolyzed (broken) by lysozyme, the entire contents of phage into the host (bacterial cells). Phage and bacterial DNA damage and control.
2. Replication phase (synthesis phase)
Phage DNA entered into the formation of DNA (replication) using bacterial DNA as a material, and form a protein coat. Then formed hundreds of new viral DNA molecules complete with envelope.
3. Phase Liberation new phage viruses / phase lysis
After the newly formed phage, bacterial cells would burst (lysis), so out the new phages. The number of new viruses to reach around 200. Bacteriophage particle formation takes about 20 minutes.
b. Lysogenic infection / lysogenic cycle
Lysogenic cycle through the following phases:
Viruses can only multiply in living cells or tissues. Therefore, the virus infects a bacteria cell, animal cell, or plant cells to reproduce. Mode of reproduction is called a virus proliferation or replication.
In Bakteriofage reproduction can be divided into two kinds, namely lytic cycle and lysogenic cycle. In the lytic cycle, the virus will destroy the stem cells after successful reproduction, whereas in the lysogenic cycle, the virus does not destroy bacterial cells but the viral DNA integrated into bacterial cells, so that if the bacteria divide or multiply split virus, too.
In principle, how the proliferation of viruses in animals and in plants similar to that which took place on bakteriofage, namely via the phase of adsorption, synthesis, and lysis.
a. Lytic infection / lytic cycle
Lytic cycle through the following phases:
1. Phase adsorption and infection
With the tip of its tail, phage attached to or infecting certain parts of the bacterial cell wall, the area was called the receptor (receptor site: receptor spots). This area is typical for a specific phage, and phages of other species can not be attached in place. Viruses attacking the bacteria do not have the enzymes for metabolism, but rnemiliki lysozyme that function damage or pierce the cell walls of bacteria.
After the wall sei bacteria hydrolyzed (broken) by lysozyme, the entire contents of phage into the host (bacterial cells). Phage and bacterial DNA damage and control.
2. Replication phase (synthesis phase)
Phage DNA entered into the formation of DNA (replication) using bacterial DNA as a material, and form a protein coat. Then formed hundreds of new viral DNA molecules complete with envelope.
3. Phase Liberation new phage viruses / phase lysis
After the newly formed phage, bacterial cells would burst (lysis), so out the new phages. The number of new viruses to reach around 200. Bacteriophage particle formation takes about 20 minutes.
b. Lysogenic infection / lysogenic cycle
Lysogenic cycle through the following phases:
1. Phase adsorption and infection
Phage attached to a specific place. Viruses penetrate the bacteria and then release its DNA into the body of bacteria.
2. Merging phase
Viral DNA together with DNA of bacteria to form a prophage. In the form of prophage, most genes are in the inactive phase, but at least acla one gene that is always active. Active genes function to encode protein receptors that function to keep some prophage genes are inactive.
3. Phase splitting
When bacteria divide, prophage join split so that two daughter cells also contain a bacterial prophage in his cell. This will take place continually during the bacterial cells contain prophage divide. So it is clear that the virus does not occur cell division, but there was the preparation of materials virus (phage) which comes from material that already exists in bacterial cells that are attacked.
a. Diseases in plants caused by viruses
1. Mosaic, a disease that causes yellow spots on leaves of plants such as tobacco, soybeans, tomatoes, potatoes and several kinds of pumpkins. The disease is caused by Tobacco Mosaic Virus (TMV).
2. Yellows, a disease that attacks the plant daisies.
3. Leaf roll, occurs in tobacco, cotton, and radish that attacked the virus TYMV.
4. Tungro disease (Tungro virus) in rice.
5. Filter vessel degeneration disease in citrus (citrus vein phloem degeneration virus (GO).
b. Diseases in animals caused by viruses
1. Newcastle disease, the type of disease affecting the poultry, especially chickens.
2. Foot and mouth disease, the type of disease affecting cattle and buffalo.
3. Cancer disease in chickens by Rous sarcoma virus (RSV).
3. Cancer disease in chickens by Rous sarcoma virus (RSV).
4. Rabies disease, the type of disease affecting dogs, cats and monkeys.
5. Polyoma, cause tumors in animals.
6. Adenovirus, the cause of tumors in certain animal.
5. Polyoma, cause tumors in animals.
6. Adenovirus, the cause of tumors in certain animal.
c. Human disease caused by virus
1. lnfluenza
The cause of influenza is a virus orthomyxovirus shaped like a ball. Influenza virus is transmitted through the air and into the human body through the respiratory tract.
1. lnfluenza
The cause of influenza is a virus orthomyxovirus shaped like a ball. Influenza virus is transmitted through the air and into the human body through the respiratory tract.
2. Measles
Measles is caused by a virus that does not rnengandung paramyxovirus
3. Chickenpox
Chicken pox is caused by a virus herpesvirus varicellae.
4. Hepatitis
Hepatitis (liver inflammation) caused by viral hepatitis. There are 3 types of viral hepatitis are hepatitis A, B, C for modern day (non-A, non-B).
5. Polio
Polio is caused by poliovirus
6. Goitre
The disease is caused by a paramyxovirus
7. AIDS
AIDS (Acquired Immune Deficiency Syndrome) is decreased immune system caused by the virus HIV (Human Immunodeficiency Virus).
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