Virology Flashcards by Amanda Krauss

What are the components of a virus?

protein and nucleic acid (DNA or RNA)

How well did you know this?

Not at all

Perfectly

What is the function of the protein capsid?

formed by capomers
protects nucleic acid
attachment of virus to cell surface receptors

How well did you know this?

Not at all

Perfectly

What is an envelope?

lipid bilayer with protein spikes that function as antigens

How well did you know this?

Not at all

Perfectly

What is an example of a big and small sized virus?

parvo-small

pox-big

How well did you know this?

Not at all

Perfectly

What is unique about the helical shaped virus?

must have an envelope

How well did you know this?

Not at all

Perfectly

Where are segmented genomes found?

RNA

How well did you know this?

Not at all

Perfectly

What is a dsRNA virus?

reovirus

How well did you know this?

Not at all

Perfectly

What is a ssDNA virus?

parvo

How well did you know this?

Not at all

Perfectly

What is a monolayer?

normal growth that exhibits contact inhibition

How well did you know this?

Not at all

Perfectly

What is neutral red staining?

stains viable cells without killing

How well did you know this?

Not at all

Perfectly

What is a multilayer?

transformed by tumor virus to not exhibit contact inhibition

How well did you know this?

Not at all

Perfectly

What is multiplicity of infection?

number of infectious virus particles added per cell to initiate infection

How well did you know this?

Not at all

Perfectly

What is cytopathic effect and what are some examples?

what happens to the cell after infection

lysis
slow death
transformation

How well did you know this?

Not at all

Perfectly

What is a plaque assay?

quantify lytic viruses by counting plaques (PFU)

How well did you know this?

Not at all

Perfectly

How do you quantify tumor derived viruses?

focal points (FFU) because they changed monolayer into multilayer

How well did you know this?

Not at all

Perfectly

What does hemagglutination measure?

infectious and noninfectious

How well did you know this?

Not at all

Perfectly

How can infected cells be determined?

hemadsorption-heme attaching via viral proteins
immunofluorescence binds specifically
LD50

How well did you know this?

Not at all

Perfectly

What is tropism?

specificity

How well did you know this?

Not at all

Perfectly

What is viropexis?

phagocytic engulfment of virus

vacuole uncoats the capsid of the virus

How well did you know this?

Not at all

Perfectly

What is fusion?

merging of lipid bilayers (helical must always undergo fusion)

How well did you know this?

Not at all

Perfectly

What is the difference between early and late proteins?

early made before replication (enzymatic)

late made after replication (structural)

How well did you know this?

Not at all

Perfectly

What are non-infectious progeny?

empty capsid

noncleaved-improper maturation

How well did you know this?

Not at all

Perfectly

What is a defective interfering particle?

after high MOI some lack nucleic acid components, use helper virus to replicate and defective number increases because they outcompete the helper

How well did you know this?

Not at all

Perfectly

What are examples of inclusion bodies?

Negri-rabies

Guarnieri-small pox

How well did you know this?

Not at all

Perfectly

What are the subfamilies of herpes?

alpha-HSV, VZ beta-CMV gamma-EB

What is the structure of herpes?

dsDNA

How does herpes replicate?

a binds to a' to form a circle | rolling circle forming concatmer

What is the receptor for herpes?

heparin sulfate

What are the different proteins?

alpha-regulatory beta-enzymatic gamma-structural

Where does assembly of herpes virus occur?

formation in nucleus | capsid passes through nuclear membrane

What are the different serological types of herpes?

HSV1 for oral | HSV2 for genital

What is the primary infection for HSV1?

gingivostomatitis-vesicular lesions in all parts of the oral cavity

What are the differences in CNS involvement between neonate and adults?

viremia in neonates | adult-spead to temporal lobe and cause necrosis

What ganglia do the herpes virus usually become latent in?

HSV1-trigeminal | HSV2-sacral

What is a split vaccine?

purified for higher antigenicity

How can you diagnose HSV?

Tzanck smear-look for inclusions | serological-PCR

How do you treat HSV?

acyclovir-inhibits DNAP but requires viral kinase and cellular kinase Foscarnet-binds to active site

What does varicella look like?

crops of vesicular lesions

What is Reye's syndrome?

complication from administering aspirin to children | leads to hepatic failure

What does shingles look like?

unilateral along a single dermatome | resides in DRG

What are the two groups of picornavirus?

enterovirus-gut (acid stable) | rhinovirus-mouth (acid labile)

What is the structure of picornavirus?

single strand non-segmented RNA positive polarity no envelope

What is the cap of picornavirus?

Vpg at 5' end

How does picornavirus attach?

CD155, lose VP4

What is the internal ribosome entry site?

essential for translation

When can translation occur?

when Vpg is missing

What is the product of 3D?

RNAP

What is a replicative intermediate?

product in replication | ex. going from positive to negative to positive requires a negative intermediate

What is the structure of orthomyxovirus?

ss negative RNA in 8 segments envelope with 2 glycoproteins (HA and NA) RNA dependent RNAP

How does orthomyxovirus attach?

sialic acid via HA

Where does the mRNA cap come from in orthomyxo?

donated from cellular mRNA in the nuclear phase

Where do the HA and NA proteins accumulate?

in the golgi (came from the RER)

What happens if HA is not cleaved?

non-infective

What does NA play a role in?

budding of progeny | lowers mucus viscosity

What is antigenic sing

strongest immuno response to first subtype

What are the subfamilies within the retroviridae?

oncoviridae-tumor virus lentivirus-slow virus spumavirinae-human foamy retroviruses, found in striated muscles

What is the structure of retroviruses?

helical nucleocapsid plus icoshedral or cylindrical outer capsid carries RNA dependent DNAP, RNAse, integrase (in pol gene)

What is the genome of retroviruses?

ssRNA, 2 identical 35 RNAs linked with cellular transfer RNA

Where does replication take place?

cytoplasm and nucleus

What is the provirus?

dsDNA that is integrated using integrase | transported to the cytoplasm

What is the role of the long term repeat?

flanks the provirus | serve as reulatory protein sites

What are the transcription products?

35 gag 28 env 21 onc

What is unique about retroviruses?

can create progeny and transform

What are the differences between chronic and acute leukemia?

chronic does not have an oncogene, has normal envelope | acute does have oncogene but lacks envelope (requires helper virus to supply the envelope)

What are mechanisms of activating a proto-oncogene?

chemical carcinogen insertion-LTR upregulate translocation-enhancer in new location (Burkitts lymphoma)

What is a tumor suppressor gene?

Retinoblastoma (phosphorylated state cell progresses to S phase)

What transports CMV and EBV?

lymphocytes

What is the inclusion body in CMV?

owl eye inclusion body

What is the nucleic acid profile of CMV?

DNA and RNA

What is cytomegalic inclusion disease?

congenital CMV infection | infects visceral organs

What is the heterophile antibody test?

negative in CMV but positive in EBV | EBV reacts to random stuff including horse blood

What are the torch infections?

``` toxoplasmosis other (listeria) rubella CMV Herpes ```

Where does EBV replicate?

in B cells, entry via CD21

What are two diseases associated with EBV?

Burkitts lymphoma nasopharyngeal carcinoma (also oral hairy leukoplakia and Hodgkins lymphoma)