lecture 3 part 2 picorna, rhino, corona Flashcards
state the envelope, capsid, and genome of the picornavirus
envelope – no envelope
capsid – icosahedral
genome: linear mRNA genome. small, (+) ssRNA viruses
what is unique about picornaviruses
they are VERY resistant to harsh conditions – ie: type of picornavirus is enterovirus (intestines)
where are picorna viruses replicated and assembled?
in the cytoplasm
which type of virus is a very large family of viruses
picornavirus
how are picornaviruses transmitted?
oral fecal route
are picorna viruses lytic or not lytic?
lytic viruses with specific tissue tropisms
explain the replication scheme of picornaviruses (how it makes protein and how it makes genome)
makes protein:
ssRNA(+) virus – directly binds to the ribosome to make viral protein
makes genome:
picornaviruses encode their own RNA dependent RNA polymerase.
genomic (+)ssRNA is converted to (-)ssRNA as a template for generating copies via RNA dependent RNA polymerase.
the template (ssRNA(-)) is then converted back into ssRNA(+) via RNA dependent RNA polymerase to be packaged into new viruses
name the 5 different groups of picornaviruses
enteroviruses
rhinovirus (common cold)
cardiovirus
aphthovirus
hepatovirus (HEPATITIS A)
name 4 enteroviruses
poliovirus
coxsackie A virus
coxsackie b virus
echovirus
which virus prefers cooler temperatures?
the rhinovirus
can rhinoviruses tolerate the GI tract?
no
Rhinoviruses use _______ as a rhinoviral receptor
ICAM-1
rhinovirus is the #1 cause of…
common cold and upper respiratory tract infections
where does the rhinovirus primarily replicate?
in the nose
how can rhinovirus be acquired?
by INHALATION or by fomites (objects that carry infection)
what is the name of the gene on the rhinovirus that inhibits eIFs to block the translation of host proteins at the ribosome?
2A
state the envelope and genome of the coronavirus
envelope – has envelope with glycoproteins that form club-like projections called CORONA. these corona enable the virus to have resistance against acids of the GI tract
genome – (+)ssRNA virus. long, flexical, helical genome
coronaviruses infect…..
upper respiratory tract epithelial cells
newly made corona viruses are released from the host cell through what mechanism?
exocytosis
do coronaviruses remain local or do they move? explain
USUALLY they remain local. this is so bc they grow best at temperatures less than our physiological temperature
RHINIVIRUSES are the 1st most common cause of common cold.
what is the second most common cause of the common cold?
coronaviruses
SARS and _____ are results of coronaviruses
MERS – middle east respiratory syndrome
SARS – severe acute respiratory syndrome
explain the replication scheme of coronaviruses (how it makes viral proteins and more genome)
same as picornaviruses – both are (+)ssRNA
ssRNA(+) virus directly binds the host ribosome to produce viral proteins
to make genome…
RNA dependent RNA polymerase converts the genomic ssRNA(+) to ssRNA(-) to serve as a template for generating more copies. the same enzyme – RNA dependent RNA polymerase – then converts this ssRNA(-) to ssRNA(+) to be packaged
name the proteins of coronaviruses
L – rna polymerase
HE – hemagglutide esterase
S – spike/attachment protein
E – envelope protein
M – matrix protein
N – nucleocapsid; RNA binding protein
