Virology Quiz 1

loroo's version from 2016-09-10 22:42

Section 1

Question Answer
basic steps of viral replicatoinattatchment, penetration, uncoating, transcription, translation,replication, assembly of virons, release
dna viral replicationmost dna virus replicate in the nucleus and use RNA ploly II to transcribe DNA
rna viral replicationmost rna virus replicate in the cytoplasm. nuclieic acid must act as mrna or carry own RdRp
two cellular enzymesdddp, and ddrp
two viral enzymesrddp (retrotrascriptase), rdrp (rna virus), ddrp (dna virus that replicate in cytoplasm)

Section 2

Question Answer
attatchment akaviral absorption
viral envalop or capsid havereceptors
receptors on viral envalope connectto complementary receptors on the cell membrane

Section 3

Question Answer
viral penetration whenviral capsid or genome enters the host cells cytoplasm
two diff types of membrane penetratoinmembrane fusion or endocytosis
most naked virusesendocytose because they dont have an envalop to fuse with the cell membrane
envoloped virusesenter via membrane fusion
uncoating can bepartial or complete
place it occurs isin cytoplasm or nucleus

Section 4

Question Answer
dna virus that replicate in nucleus useddrp to make mrna
what do dna virus that replicate in cytoplasm bring ddrp that they bring with them
what type of virus rna just bind right to ribosome+
once the mrna is translated for an rna virus what happensnormally they code for thier own viral polymerase ot replicate thier genome (rdrp)

Section 5

Question Answer
papo, adeno, herpeshave double stranded dna, use cell enzymes and the RNA transcript has polycistronic messages that are spliced and turned into diff messages
which famils have poly cistronic messagespapo, adeno, herpes, parvo
pox, asafardouble stranded dna, use viral enzymes b/c repilcates in the cytoplasm, rna transcripts translated into proteins
parvosingle stranded dna, use cell enzymes to produce a double dna first then this creates a double strand with a + piece it can translate. rna message polycistronic

Section 6

Question Answer
when a rna virus is + and can code directly for a protein what does that protein normally do?code for rdrp
if the rna doesnt look like an mrna right away what needs to happenneed to transcription first from rna to mrna
translation happens first in which rna virusespicorna, flavi, toga, calci, corona
which virus that have tln happen first code for protien right awaypicorna, flavi
which rna virus bring own enzymesparamyxo, rabdo, filo, orthomyxo, arena, bunya, reo, retro
whats special about retroviruseshas two single stranded rna they are + and they bring thier own enxyme to go from RNA to DNA
+ means5'-3'
how to replicate through a DNA intermediate1.carry reverse transcriptase 2. E acts on ribonuclease and removees paretnal rna from the RNA =dna hybrid 3. then copies the negative sense ss DNA to form a linear DS DNA which has additional sequence (LTR which alllows virus to insert into hoste genome4. this DS DNA then integrates into cellular chromosomal DNA
ltrlont term repeats
proviralwhen virus inserts into host

Section 7

Question Answer
cap is what7 methy guanosines
cap is added for whatformation of stable complex
poly a tail50-100 a's added for recognition signal for transport and protects mrna from degredation
methylationmethyl group added to dan
splicingremoval of introls and exons
post translational modificationsphosphorylation, glycosylationm proteolytic cleavange
cellular mrnamonocistric
vial mrnapolycistronic

Section 8

Question Answer
capsidsformed spontaneously to form to encase virus in icosahedra
in helical virusesthe rna molecule assembles into a clidrical heliz bound to structural protein (pearl necklace)
naked virusesaccumulate in the cell or nucleus until they lyse cell
enveloped virusesexit by budding or exocytosis
which viruses exit through exocytosisflavi, cornoa, artera, bunya carry envelops from golgi or rer

Section 9

Question Answer
acuteself limited infection, recover with no residual effects
latentlooks like acute, it hides and cant be dtected, immunte system cant completely get rid of it
example of acuterespitory infections
example of latentherpes, periods of shed and symptoms
chronicanimal may recover but contiue to shed virus for months to years
example of chronicfoot and mouth disease
outcome of acute infectionrecovery with residue effects, death, proceed to chronic latent infection
outcome of chronic/laten infectionsilent subclnical infections for life, long silent period, reactivation of disease
primary replicationwhere virus replicates after gaining inital entry into host, may be local but may not be and spread later
systemic spreadvia blood stream or peripheral nerves
cell tropismviral affinity for specific body tissues
cell tropism depends oncell receptor for virus, cell transcription factors, ablity of cell to support replication, physical barriers, local temp, body secretion, digestive enzymes

Section 10

Question Answer
cells can respond to viral infections in 3 waysno change, death, transformation
direct cell damagefrom copetition of virus mrna for cellular ribosomes, diverson of cell energy, shutoff of cell macromolecule, competition of viral proopters
idirect cell damageintegration of viral genome, induction of mutaions, inflammation

Section 11

Question Answer
diarhea occurs when rapid destruction of epi cells cause immature transitional cells to replace them, cant absorb
newborns have worst prognosis whyconstant prescen of high conentrations of milk lactose in intestinal lumen
how are villi affectedmost cases become blunted
which ab is better against protecting against git viruses iga