BIOC20 FINAL EXAM QUESTIONS
COMPLETE WITH 100% CORRECT
ANSWERS
\.Negative strand RNA genomes - ANSWERS-Single stranded
Cannot be directly translated
To make proteins, the negative strand must be used to make a complimentary
positive strand
\.How to convert negative strand to positive strand? - ANSWERS-Original genome
(negative sense strand) -> conversion using RNA dependent RNA polymerase ->
complimentary positive sense strand
\.Positive stranded RNA virus - ANSWERS-Does not need an RNA polymerase, can
be directly translated and can produce RNA and make RNA
\.What codes for the Viral RNA polymerase? - ANSWERS-The Negative stranded
RNA virus codes for their own RNA polymerase (they do NOT use the cell's
polymerase bc it can only read DNA)
\.How does the RNA polymerase get created? - ANSWERS-Negative strand is
accompanied by the RNA polymerase which reads the negative strand and creates
,the positive strand. The positive strand can code for multiple viral proteins
(including the RNA polymerase) as well as more complimentary negative strands
\.Ribonuceleo-protein complex - ANSWERS-Negative strand RNA genome + RNA
polymerase (RNA polymerase is made up of diff components)
\.Negative Stranded RNA Viral Families (list 5) - ANSWERS-Paramyxoviruses
Rhabdoviruses
Filoviruses
Bunyaviruses
Influenza viruses (umbrella virus)
\.Influenza Virus Proteins (individual segments) - ANSWERS-Entire genome exists
as 8 individual segments
Each segment codes for a different protein
\.What does the RNA polymerase complex consist of? - ANSWERS-Complex
consists of PA, PB1, and PB2
\.What do Influenza Virus Genome segments 1,2 and 3 code for? - ANSWERS-
Segments 1,2,3 code for the components that make up the RNA polymerase
complex
\.What does Segment 4 code for? - ANSWERS-Genome segment 4 corresponds to
hemaglutinin (one of the enveloped proteins)
,\.What does Segment 5 code for - ANSWERS-nucleocapsid proteins
\.What does segment 6 code for - ANSWERS-Neuraminidase (another viral
protein)
\.What does segment 7 code for - ANSWERS-2 diff proteins:
1) M2 (ion channel)
2) M1 matrix protein
\.What does segment 8 code for? - ANSWERS-NS2 proteins
\.Is the Influenza virus enveloped or non enveloped? - ANSWERS-Influenza is an
enveloped virus
\.What is a nucleocapsid in Influenza? - ANSWERS-When the genome binds to the
capsid proteins. However, for influenza, we refer to the capsid protein itself as a
nucleocapsid protein (NP)
\.How does Influenza enter a cell - ANSWERS-Dock at target cell and is taken in by
vesicles that pinch inwards from plasma membrane. Now the virion is within an
endosome and as the endosome matures, the enveloped virus fuses with the
endosomal membrane to dump its nucleocapsid out into the cytoplasm
\.How does Influenza fusion work? - ANSWERS-Viral envelope and envelope
protein attached to envelope -> protein undergoes conformational change after
, being exposed to acidic environment -> fusion peptides are exposed and inserted
into the endosomal membrane -> more viral envelope proteins cluster together
and fuse as well -> jack-knife confirmation occurs (proteins bend and pull in
endosomal membrane -> creation of fusion channel for a nucleocapsid to enter
\.Which protein mediates the fusion between the viral envelope and the
endosomal membrane? - ANSWERS-The hemagglutinin protein
\.What are the names of the Hemagglutinin (HA) protein domains? - ANSWERS-2
domains:
HA1 domain
HA2 domain
\.what is the function of the HA1 domain? - ANSWERS-responsible for docking
(has a sialic acid binding domain)
•Domain binds to the sialic acid on receptors on the plasma membrane
•Nucleocapsid is taken in by the vesicles that pinch in from the plasma membrane
•Now in endosome and waiting for fusion to occur
\.What is the function of the HA2 domain - ANSWERS-responsible for fusion
•Activated when cleavage occurs between HA1 and HA2
Allows for HA2 to insert itself into the endosomal membrane
\.what are the three steps of membrane fusion - ANSWERS-1) binds to cell
receptor
COMPLETE WITH 100% CORRECT
ANSWERS
\.Negative strand RNA genomes - ANSWERS-Single stranded
Cannot be directly translated
To make proteins, the negative strand must be used to make a complimentary
positive strand
\.How to convert negative strand to positive strand? - ANSWERS-Original genome
(negative sense strand) -> conversion using RNA dependent RNA polymerase ->
complimentary positive sense strand
\.Positive stranded RNA virus - ANSWERS-Does not need an RNA polymerase, can
be directly translated and can produce RNA and make RNA
\.What codes for the Viral RNA polymerase? - ANSWERS-The Negative stranded
RNA virus codes for their own RNA polymerase (they do NOT use the cell's
polymerase bc it can only read DNA)
\.How does the RNA polymerase get created? - ANSWERS-Negative strand is
accompanied by the RNA polymerase which reads the negative strand and creates
,the positive strand. The positive strand can code for multiple viral proteins
(including the RNA polymerase) as well as more complimentary negative strands
\.Ribonuceleo-protein complex - ANSWERS-Negative strand RNA genome + RNA
polymerase (RNA polymerase is made up of diff components)
\.Negative Stranded RNA Viral Families (list 5) - ANSWERS-Paramyxoviruses
Rhabdoviruses
Filoviruses
Bunyaviruses
Influenza viruses (umbrella virus)
\.Influenza Virus Proteins (individual segments) - ANSWERS-Entire genome exists
as 8 individual segments
Each segment codes for a different protein
\.What does the RNA polymerase complex consist of? - ANSWERS-Complex
consists of PA, PB1, and PB2
\.What do Influenza Virus Genome segments 1,2 and 3 code for? - ANSWERS-
Segments 1,2,3 code for the components that make up the RNA polymerase
complex
\.What does Segment 4 code for? - ANSWERS-Genome segment 4 corresponds to
hemaglutinin (one of the enveloped proteins)
,\.What does Segment 5 code for - ANSWERS-nucleocapsid proteins
\.What does segment 6 code for - ANSWERS-Neuraminidase (another viral
protein)
\.What does segment 7 code for - ANSWERS-2 diff proteins:
1) M2 (ion channel)
2) M1 matrix protein
\.What does segment 8 code for? - ANSWERS-NS2 proteins
\.Is the Influenza virus enveloped or non enveloped? - ANSWERS-Influenza is an
enveloped virus
\.What is a nucleocapsid in Influenza? - ANSWERS-When the genome binds to the
capsid proteins. However, for influenza, we refer to the capsid protein itself as a
nucleocapsid protein (NP)
\.How does Influenza enter a cell - ANSWERS-Dock at target cell and is taken in by
vesicles that pinch inwards from plasma membrane. Now the virion is within an
endosome and as the endosome matures, the enveloped virus fuses with the
endosomal membrane to dump its nucleocapsid out into the cytoplasm
\.How does Influenza fusion work? - ANSWERS-Viral envelope and envelope
protein attached to envelope -> protein undergoes conformational change after
, being exposed to acidic environment -> fusion peptides are exposed and inserted
into the endosomal membrane -> more viral envelope proteins cluster together
and fuse as well -> jack-knife confirmation occurs (proteins bend and pull in
endosomal membrane -> creation of fusion channel for a nucleocapsid to enter
\.Which protein mediates the fusion between the viral envelope and the
endosomal membrane? - ANSWERS-The hemagglutinin protein
\.What are the names of the Hemagglutinin (HA) protein domains? - ANSWERS-2
domains:
HA1 domain
HA2 domain
\.what is the function of the HA1 domain? - ANSWERS-responsible for docking
(has a sialic acid binding domain)
•Domain binds to the sialic acid on receptors on the plasma membrane
•Nucleocapsid is taken in by the vesicles that pinch in from the plasma membrane
•Now in endosome and waiting for fusion to occur
\.What is the function of the HA2 domain - ANSWERS-responsible for fusion
•Activated when cleavage occurs between HA1 and HA2
Allows for HA2 to insert itself into the endosomal membrane
\.what are the three steps of membrane fusion - ANSWERS-1) binds to cell
receptor
