MICROM 301 Lecture Notes - Lecture 2: Lipid Bilayer, Electron Microscope, Veterinary Virology
MICRO MIDTERM EXAM #2 NOTES
FRIDAY (4/20):
INDEPENDENT STUDY
- Viruses
oCan only multiply within a host cell
Uses host cell’s machinery
Viruses can’t harvest their own energy
Can’t synthesize proteins
Uses machinery to produce VIRAL PARTICLES
oNon living
oGenetic info (EITHER DNA or RNA)
oWrapped in a protective protein coat
oCan only be seen with an electron microscope
Very small in size
Largest virus = smallest bacteria
- Two general groups of viruses
oInfect Eukaryotic Cells
oInfect Prokaryotic Cells
aka bacteriophage or phage
model organism to understand animal viruses
bacteriophages are easy to cultivate in lab
used for DNA transfer
horizontal gene transfer
used to destroy bacteria!! ex. pathogens on food
- Viral Architecture
oGenome (DNA or RNA) surrounded by protein coat (capsid)
oGenome: DNA or RNA; double-stranded or single-stranded
oVirion: viral particle, consists of nucleic acid
oCapsid: protein coat for protection
oNucleocapsid: capsid & the nucleic acid (DNA or RNA)
- Two general types
oNon-enveloped viruses (aka naked viruses)
No envelope so spikes come out farther
More resistant to drying and chemicals
oEnveloped viruses
Usually only viruses that infect ANIMAL cells
Has a LIPID BILAYER outside the capsid
Their progeny also have the envelope
Much more susceptible to drying and chemicals
Their spikes are in the envelope so when the lipid envelope gets
damaged, are no longer infectious
- Shapes
oIcosahedral: appear spherical with electron microscope
find more resources at oneclass.com
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Document Summary
Viruses: can only multiply within a host cell. Uses machinery to produce viral particles: non living, genetic info (either dna or rna, wrapped in a protective protein coat, can only be seen with an electron microscope. Two general groups of viruses: infect eukaryotic cells, infect prokaryotic cells aka bacteriophage or phage. Model organism to understand animal viruses bacteriophages are easy to cultivate in lab. Used for dna transfer horizontal gene transfer. Two general types: non-enveloped viruses (aka naked viruses) No envelope so spikes come out farther. More resistant to drying and chemicals: enveloped viruses. Usually only viruses that infect animal cells. Has a lipid bilayer outside the capsid. Much more susceptible to drying and chemicals. Their spikes are in the envelope so when the lipid envelope gets damaged, are no longer infectious. Shapes: icosahedral: appear spherical with electron microscope. Micro midterm exam #2 notes like a soccer ball with triangular subunits: helical: appear cylindrical, complex (typically phages): head & body.
