lecture 3 part 2 picorna, rhino, corona

Question 1

state the envelope, capsid, and genome of the picornavirus

Answer 1

envelope – no envelope
capsid – icosahedral
genome: linear mRNA genome. small, (+) ssRNA viruses

Question 2

what is unique about picornaviruses

Answer 2

they are VERY resistant to harsh conditions – ie: type of picornavirus is enterovirus (intestines)

Question 3

where are picorna viruses replicated and assembled?

Answer 3

in the cytoplasm

Question 4

which type of virus is a very large family of viruses

Answer 4

picornavirus

Question 5

how are picornaviruses transmitted?

Answer 5

oral fecal route

Question 6

are picorna viruses lytic or not lytic?

Answer 6

lytic viruses with specific tissue tropisms

Question 7

explain the replication scheme of picornaviruses (how it makes protein and how it makes genome)

Answer 7

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

Question 8

name the 5 different groups of picornaviruses

Answer 8

enteroviruses
rhinovirus (common cold)
cardiovirus
aphthovirus
hepatovirus (HEPATITIS A)

Question 9

name 4 enteroviruses

Answer 9

poliovirus
coxsackie A virus
coxsackie b virus
echovirus

Question 10

which virus prefers cooler temperatures?

Answer 10

the rhinovirus

Question 11

can rhinoviruses tolerate the GI tract?

Answer 11

no

Question 12

Rhinoviruses use _______ as a rhinoviral receptor

Answer 12

ICAM-1

Question 13

rhinovirus is the #1 cause of…

Answer 13

common cold and upper respiratory tract infections

Question 14

where does the rhinovirus primarily replicate?

Answer 14

in the nose

Question 15

how can rhinovirus be acquired?

Answer 15

by INHALATION or by fomites (objects that carry infection)

Question 16

what is the name of the gene on the rhinovirus that inhibits eIFs to block the translation of host proteins at the ribosome?

Answer 16

2A

Question 17

state the envelope and genome of the coronavirus

Answer 17

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

Question 18

coronaviruses infect…..

Answer 18

upper respiratory tract epithelial cells

Question 19

newly made corona viruses are released from the host cell through what mechanism?

Answer 19

exocytosis

Question 20

do coronaviruses remain local or do they move? explain

Answer 20

USUALLY they remain local. this is so bc they grow best at temperatures less than our physiological temperature

Question 21

RHINIVIRUSES are the 1st most common cause of common cold.
what is the second most common cause of the common cold?

Answer 21

coronaviruses

Question 22

SARS and _____ are results of coronaviruses

Answer 22

MERS – middle east respiratory syndrome

SARS – severe acute respiratory syndrome

Question 23

explain the replication scheme of coronaviruses (how it makes viral proteins and more genome)

Answer 23

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

Question 24

name the proteins of coronaviruses

Answer 24

L – rna polymerase
HE – hemagglutide esterase
S – spike/attachment protein
E – envelope protein
M – matrix protein
N – nucleocapsid; RNA binding protein