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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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