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Virus Module Set 3
Question | Answer |
---|---|
Virus assays: | Used to determine quantity of viruses in a sample |
Two types of approaches | Count particles and measure concentration of infectious units |
Direct count: | Made with an electron microscope |
Indirect count: | Determines highest dilution of virus that causes red blood cells to clump together |
Plaque assays are | Dilutions of virus preparation made and plated on lawn of host cells |
Plaque assays measure | Number of plaques counted |
Plaque assays results are expressed as | PFU (plaque forming units) |
Virion sizes range from _____ nm on diameter | 10-400 |
Most virions must be | Viewed with an electron microscope |
All virions contain | Nucleocapsid |
Nucleocapsid is composed of | Nucleic acid (DNA or RNA) and a protein coat (capsid) |
Viruses also made up of | Envelope |
Nucleocapsid: | Nucleic acid held within protein coat |
Capsid: | Protein coat that surrounds viral genome |
Capsid function | Protects genome Aids in transfer obetween host cells |
protomer: | protein subunits that make up capsid |