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VIRUSES
By Nia Widyastuti
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Describing thecharacteristics, thereplication, and the
rolesof virus in life
Identify the characteristics of virus
Distinguish the structure of virus
Explain the virus life style
Explain the replication of virus
Explain the roles of the harmful and the harmless viruses
BASIC COMPETENCY INDICATOR
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HISTORY OF THE SEARCH FOR VIRUS
1883, Adolf Mayer (Germany) do research to tobacco plant have mosaic disease can cause tobacco plant become dwarf and leaves have spotted. Conclusion : new kind of bacteria
1892, Dmitri Iwanowski (Russian) do filter extract tobacco leave with filter so bacteria or other micro organism can’t infection plant tobacco in fact extract tobacco have been filtered but tobacco plant infection mosaic disease. Conclusion : pathogen bacteria
1893, Martinus W. Beijerink (Dutch) he assumed that there are agent can infection tobacco plant, he called that agent is filterable virus because can out from bacteria filter and can’t to have seen with light microscope
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CHARACTERISTICS OF VIRUSES
Viruses are not cell Viruses extremely small (0,05-0,2 µm or 50x smaller than
bacteria size. To observe viruses need electron microscope Contain some materials found in cells, made of a core of
nucleic acid surrounded by a protein DNA or RNA Can’t do reproduction it self Can’t do metabolisms it self Can be crystalloid
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DIFFERENCE OF VIRUS WITH CELL
Only have one type nucleic acid (RNA or DNA)
Can’t do reproduction it self Don’t have metabolisms it
self
Body cell have two type nucleic acid DNA and RNA
Can do reproduction Have metabolism system
VIRUS CELL
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STRUCTURE BODY OF VIRUS
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2 3 3
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1. Protein coat
2. Nucleic acid
3. Head
4. Wrapper tail
5. Tail fiber
Model of a virus Information Picture
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SHAPE OF VIRUSES
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REPRODUCTION OF VIRUSES
Absorption
(virus attaches to cell) Penetration
(virus DNA enters cytoplasm cell)
Replication and synthesis
(virus directs cell to make new viruses)
Shape of new virus
(arrange nucleic acid and protein virus)
Released
(cell burst releasing new virus)
Process lyshogenic cycle
similar with lytic cycle step
but in in step replication
there are step addition or
insertion genetic material
virus in bacteria material
which called profage
LYTIC CYCLE LYSHOGENIC CYCLE
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CLASSIFICATION OF VIRUS
Based on hospes cell (sel inang) virus divided into three, they are :
1. Bacteria Virus (virus which infection bacteria cell)
2. Animal Virus (virus which infection animal cell)
3. Plant Virus (virus which infection plant cell)
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DISEASE IN ANIMAL CAUSED BY VIRUS
Kind of Virus Kinds of Disease
New castle disease Tetelo in aves
Rhabdovirus Rabies in dog, monkey
Rous sarcoma virus Cancer in chicken
Herpesvirus simiae Herpes in monkey
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Herpes
Tetelo
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DISEASE IN PLANTS CAUSED BY VIRUS
Kind of Disease Kind of Virus
Spotted in leave tobacco Tobacco mosaic virus
Spotted in cabbage Cauliflower mosaic virus
Decrease growth in potato plant Potato yellow dwarf virus
Decrease growth in potato plant Rice dwarf virus
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Potato yellow dwarf virus
Tobacco Mosaic virus
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DISEASE IN HUMAN CAUSED BY VIRUS
Disease Kinds of Virus
Herpes oral Herpesvirus simplex tipe I
Smallpox Poxviruses
Hepatitis B Hepadna virus
Encephalistis, Rubela, Chikungunya
Togaviruses
Rabies Rhabdovirus
Influesza Orthomyxoviruses
Leukemia Retroviruses; HTLV
Measles Paramyxoviruses
Ebola Filovirus
Polio, hepatitis A Enterovirus
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Hepatitis BEbola
Herpes Oral
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USES OF VIRUS
Insect Control
Some viruses cause disease in insects. Scientists are trying to use these viruses to kill insects that damage crops. In time, such viruses may replace insecticides.
Cell Research
Scientist study viruses to understands DNA, RNA, and other cell compounds. Such research may add to our knowledge of cell activities.
Control of Viral Diseases
Scientists use some virus to produce vaccines. Vaccines are substances that help your body defend against diseases. Several vaccines are made from chemical treated viruses. These vaccines are injected into the body. The body then produces substances that protect against these viruses
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Thank You for your Attention
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