Bio 260 viruses
1. General Characteristics of Viruses: -Obligatory intracellular parasites
-DNA or RNA
-protein coat
-some enclosed by envelope
-some have spikes
-Most only specific of cells in one host
-host range determined by specific host attachment sites and cellular factors
2. what units do we measure viruses?: nm
3. Microbes discovered: 1600's
4. microbes linked to disease 1800-1900s: -fungi and protozoa kill silkworms
bacteria kills cattle
-handwashing disinfectants antibiotics-antibacterial
vaccination(Jenner-smallpox; Pasteur-rabies) but no understanding of why it worked
5. Virus inferred in 1892 (Dmitri Ivanovsky): -
From Latin and late middle English for venom or poison
1/7
, -Tobacco mosaic virus-plant infection
New bacterial filter did not prevent infection
6. Membrane filtration: removes microbes >0.22um
-will not remove viruses
7. To remove viruses: -autoclave
-chemicals
-dry heat
8. virus structure: -Virion -one virus particle
-chemical composition-protein, nucleic acid, (lipid)
-Structural components-genome, capsid, (envelope)
9. Nucleic acid (virion structure): RNA or DNA
10. Capsid: -protein coat around nucleic acid
11. Spikes: -grab onto host
-proteins
-spikes and receptors are specific
12. Optional envelope: phospholipid bilayer
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1. General Characteristics of Viruses: -Obligatory intracellular parasites
-DNA or RNA
-protein coat
-some enclosed by envelope
-some have spikes
-Most only specific of cells in one host
-host range determined by specific host attachment sites and cellular factors
2. what units do we measure viruses?: nm
3. Microbes discovered: 1600's
4. microbes linked to disease 1800-1900s: -fungi and protozoa kill silkworms
bacteria kills cattle
-handwashing disinfectants antibiotics-antibacterial
vaccination(Jenner-smallpox; Pasteur-rabies) but no understanding of why it worked
5. Virus inferred in 1892 (Dmitri Ivanovsky): -
From Latin and late middle English for venom or poison
1/7
, -Tobacco mosaic virus-plant infection
New bacterial filter did not prevent infection
6. Membrane filtration: removes microbes >0.22um
-will not remove viruses
7. To remove viruses: -autoclave
-chemicals
-dry heat
8. virus structure: -Virion -one virus particle
-chemical composition-protein, nucleic acid, (lipid)
-Structural components-genome, capsid, (envelope)
9. Nucleic acid (virion structure): RNA or DNA
10. Capsid: -protein coat around nucleic acid
11. Spikes: -grab onto host
-proteins
-spikes and receptors are specific
12. Optional envelope: phospholipid bilayer
2/7
