Ch 5&6 Virus structure Flashcards
HIV virion contains viral reverse transcriptase, while SARS coronavirus virions do not contain viral RNA polymerase. Which of these proteins are considered STRUCTURAL proteins
HIV reverse transcriptase only
What are cytokines?
regulatory proteins that mediate intracellular communication during antiviral defense. Induce antiviral state & regulate adaptive immune response. Bind to specific receptors & activate gene expression
What’s the difference between necrosis and apoptosis
Necrosis release cellular components & create localized inflammation. Apoptosis programmed cell death via complex molecular cascades, condensation, chromatin clumping, blebbing cellular content and phagocytosis
What are helical capsids
simple arrangements of virus particles, example tobacco mosaic virus. Identical protein subunits, rotational symmetry
T=1 icosahedral capsids are composed of how many capsid proteins
60 capsid proteins
What determines the shape of a virus
virus capsid
virus families always include viruses infecting the same kingdom
false
How do you calculate the MOI Multiplicity of infection
infectious agent (virus) / target cells. example 5 million virus particles divided by 1 million target cells
MOI is calculated by what …
dividing number of viruses by number of cells
In cell penetration, which is energy dependent, direct fusion (only enveloped viruses) is pH ___ while endocytosis (all viruses) is pH ___
direct fusion pH-independent (fuse directly at cell so don’t rely on pH) endocytosis pH-dependent (needs certain pH to fuse virus into intracellular vacuoles)
For enveloped viruses, the membrane fusion formation after endocytosis is pH __
pH dependent
T/F Viral attachment to the host requires energy
true
the target receptor molecules on cell surfaces are what? (3 options)
proteins, carbohydrate residues, or glycolipids
