| Which pattern of viral pathogenesis? Follows acute infection, virus
persists in noninfectious form w/ intermittent periods of reactivation
& shedding. |
Latent infection |
| Which pattern of viral pathogenesis? Viral infection which is rapidly
cleared by host immune response. |
Acute infection |
| What are the five patterns of Viral Pathogenesis? |
1. Acute infection; 2. Latent infection; 3. Chronic Infection; 4. Slow
Chronic infection w/out acute infection (ie prions) 5. Transformation (ie
Cancer) |
| Which virus(es) are: Relaxed circular, partially duplexed DNA virus?
(1) |
HBV |
| Which virus(es) are: Double-stranded RNA virus? (2) |
reovirus, rotavirus |
| Which virus(es) are: Segmented Negative Strand RNA virus (1) |
Orthomyxovirus (influenza) |
| Which virus(es) are: Non-segmented negative-strand RNA virus (3) |
Paramyxoviruses (RSV, Measles, Mumps), Rhabdovirus, Filovirus |
| Which virus(es) are: Retrovirus (1) |
HIV |
| Which virus(es) are: Positive-strand RNA virus coding for one or more
subgenomic mRNAs? (4) |
Coronavirus, Togavirus, Calicivirus, Hepatitis E |
| Which virus(es) are: Positive-strand RNA virus coding for one
genome-sized RNA? (2) |
Picornaviruses, Hepatitis C |
| Which virus(es) are: Single-stranded DNA virus? (1) |
Parvovirus |
| Which virus(es) are: double-stranded DNA virus that replicates in the
cytoplasm?(1) |
Poxvirus |
| Which virus(es) are: double-stranded DNA virus that replicates in the
nucleus (circular or linear) (3) |
Herpesvirus, adenovirus, papillomavirus |
| T or F: Retroviruses can reproduce without cell death. |
True, in certain cell types |
| T or F: The process of viral budding alone will cause cell death. |
False; The loss of normal cellular function required for survival is
what leads to death. |
| What are the 2 ways for release of the virus from a cell? |
Cell death--for naked capsid viruses that lack a lysis mechanism
(don't need protection of envelope; Budding--acquire their membrane by
budding either through the plasma membrane, nuclear membrane (herpes), or
golgi or early endosome network (poxvirus) |
| What stages make up the "eclipse (flat line)" state of the one-step
growth curve? |
Uncoating, replication and assembly, & maturation |
| Where does assembly take place for the influenza virus? |
Cytoplasm |
| Where does assembly take place for the herpes virus? |
In the Nucleus |
| What is the location in the cell where assembly initiates? |
The Packaging Site |
| During encapsidation, Individual structural subunits or protomeres are
preformed into __________ in preparation for final assembly. |
Capsomeres |
| T or F: During encapsidation, self-assembly of component parts occurs
in a random fashion |
False; it's a stepwise and ordered fashion |
| What is a long polypeptide chain that is translated from a single
transcript with a single ribosome binding site? |
Polyprotein |
| What is the process in RNA that removes intervening sequences that do
not encode for protein product? |
Splicing |
| The coding DNA strand is always a ________ polarity. |
Negative - |
| RNA molecules which are complementary to mRNA have a ______ polarity.
|
Negative - |
| mRNA strands have a ______ polarity. |
(positive) + |
| In order for the virus to replicate, what must it present to the cell?
|
A viral specific mRNA that the cell can recognize and then translate.
|
| Most DNA viruses replicate in the ___________. |
nucleus (except poxviruses) |
| Most RNA viruses replicate in the ___________. |
cytoplasm |
| What is the KEY event in virus replication? |
The synthesis of viral proteins (utilizing the host's protein
synthesizing machinery) |
| During membrane fusion, the _________ fuses with the plasma membrane
of the host cell, thus releasing the __________ into the cell. |
Envelope; Nucleocapsid |
| What process does the Herpesvirus undergo to enter the cell and
undergo de-coating? |
Membrane fusion |
| What is the portion of the virus called that is surrounded by the
envelope? |
The nucleocapsid |
| What is the portion of the cell membrane called that breaks off and
surrounds the virus during receptor-mediated endocytosis? |
The endosomal vesicle (or just endosome) **It is acidic, which is
critical in the release of the nucleocapsid in the influenza virus. |
| The influenza virus is critically dependent on what in order to
un-coat and begin replicating? |
A low pH. The acidified endosome of receptor-mediated endocytosis
releases the nucleocapsid into the cytoplasm. |
| What is the process called in the removal of the protective envelope
and/or capsid? |
Uncoating |
| T or F: The virus can begin replication prior to dismantleling. |
False; virus must dismantle first. |
| What type of entry: Virion envelope fuses with cellular membrane |
Fusion; (ie herpes, measles, HIV) |
| What type of entry: results in accumulation of virus particles inside
cytoplasmic vesicles (ie influenza this way) |
Receptor mediated endocytosis |
| What type of entry: entire virus crosses plasma membrane
(non-enveloped) |
Translocation |
| What are the three types of entry? |
1. Translocation; 2. Receptor-mediated endocytosis; 3. fusion |
| T or F: Penetration is energy dependent (not that type of penetration
sickos) |
TRUE |
| How do neutralizing antibodies work? |
They are specific for an antireceptor on a virus. |
| Differences in host range and tissue tropism are due most often to the
presence or absence of ___________. |
receptors |
| What is adsorption enhanced by? |
multiplicities of attachment and receptor proteins |
| Viral _________ are examples of antireceptor molecules |
spikes |
| In the process of adsorption, what are the cellular receptors composed
of? |
glycoproteins |
| What are the 3 general stages of initiation of infection? |
1. Adsorption (attachment); 2. Penetration; 3. Uncoating |
| What are the 3 steps in PCR?` |
1. Denature DNA template; 2. Anneal primers to the DNA template; 3.
Primer extension reaction; (after, you run through this cycle tons of
times to get lots of copies of the DNA template) |
