Virology Flashcards
Infectious, obligate intracellular parasite
Virus
viral particle
virion
Can a virus have both DNA and RNA?
no (one or the other)
What are virions composed of?
-RNA or DNA
-protein coat
-Envelope
virus size?
Very small
-Pass 0.2 µm filters
If the cell is lysed to spread the virus, it will not have what?
an envelope
True or false:
Viruses lack the complex energy-generating and biosynthetic systems necessary for
independent existence.
True
what are the simplest biologically active agents?
-viroids
-prions
-Single small molecule of non-coding RNA
-Plant pathogens
Viroids
Single protein molecules capable of infection
Prions
HIV —> enzyme —-> ________ transcriptase (RNA to DNA)
reverse
HIV infects what type of cells?
CD4
Infectious progeny virus particles, called _________ , are formed by de novo self-assembly from newly synthesized components.
Virions
What is the vehicle for transmission of the viral genome to the next host cell or organism, where its disassembly initiates the next infectious cycle.
-A progeny virion assembled during the infectious cycle
How can viruses be visualized?
-electron microscope
-x-ray
What is the size of viruses?
10^2 nanometers
Steps of viral infectious cycle?
-Attachment
-Penetration
-Uncoating (envelope)
-Replication: RNA –> mRNA –> more RNA
–> DNA —> mRNA
-Maturation (Assembly)
-Release (Death of cell = apoptosis)
What does ICTV stand for?
International Committee on Taxonomy of Viruses
Organization tasked with viral nomenclature
International Committee on Taxonomy of Viruses (ICTV)
virus taxonomy:
virus order –>
-virales
virus taxonomy:
subfamily —>
-virinae
virus taxonomy:
genus —->
-virus
viruses are not classified beyond _________.
species
-subspecies-level assignments or “types” are not recognized by the ICTV
What are the two systems used for viral taxonomy?
-International Committee on Taxonomy of Viruses (ICTV)
-Baltimore classification