LEcture 6 Flashcards
Viruses alwayas have a _____ and a protein coat called the _____.
genome, capsid
The most abundant microbe in the world are ____.
viruses
The size of viruses range from ___ to ____ ____.
20 to 200 nm
What are the 3 capsid variants?
- Icosahedral
- Filamentous
- Complex
Capsid with 20 triangular side, each triangle made of at least 3 identical capsid proteins.
Icosahedral capsid
Long tube of protein with genome inside capsid structure.
Fiamentous (helical) capsid`
Asymmetrical shape, mix of icosahedral and filamentous shapes capsid structure.
Complex structure
Some viruses have an _____, made of a phospholipid bilayer, to allow the virus to bind to host cells.
envelope
T/F: Viruses can have DNA and/or RNA
True
Group I virus example
poxvirus
Group I viruses have
dsDNA
Group II virus example
Parvovirus
Group II viruses have
ssDNA
Group III virus example
Epizootic Hemorrhagic Disease
Group III viruses have
dsRNA
Group IV virus example
Poliovirus
Group IV viruses have
+ssRNA
Group V virus example
Influenza
Gruop V viruses have
-ssRNA
Group VI virus example
HIV
Gruop VI viruses have
RNA retroviruses
Group VII virus example
Hepatitus B
Group VII viruses have
DNA pararetroviruses
Bacteriophage life cycle
- Attach
- Inject
- Replicate
- Synthesize capsid proteins
- Assemple progeny phage
- Lyse cell wall to release progeny
The ____-____ Experiment radioactively labeled ____ with 35S Methionine and radioactively labeled ____ with 32P Phosphate, infected E. coli, and found only 32P entered cells, not 35S.
Hershey-Chase, protein, DNA
Cycle when phage quickly replicates
Lytic cycle
Cycle when phage is dormant
Lysogenic
Bacteriophages use cell components to ______ _____.
synthesize capside
Bacteriophage progeny exit the host cell by ____ or, rearely, _____.
lysis, slow release
Eukaryotic viruses ______ to a host cell receptor and enter the cell by endocytosis (_______).
attatch, viropexis
DNA viruses must ______ to use host polymerase or replicate in cytoplasm withviral polymerase
go to cell nucleus
RNA viruses must
encode a viral polymerase
only ______ can be used at mRNA
+ssRNA
All viruses make ______ with host ribosomes
proteins
When viruses pass though the membrane, and the lipids surround the capsid to form an envelope.
Budding
What are the three “stages” or culturing viruses?
- virus binds to host
- eclipse period
- rapid rise period
What is occuring during the eclipse period of culturing viruses
The viruses make proteins, genomes, and are assembling
A colony of viruses is called a ____.
Plaque
Viruses present in all _______, often at very _____ _______.
environments, high densities
What is Naked RNA called?
Viroid
Virus particles that are just proteins are called
prions
Example of prions
Creutzfeld-Jakob
Disease
How do prionsPrion diseases are caused by the
misfolding of proteins
What part of a virus consists of a protein shell?
Capsid
Which of these is an example of a pathogen that is just nucleic acid?
Viroid
