MCB6937 Final Exam Questions And
Answers 100% Verified.
Quiz 10:
What is Dr. William Prusoff known for? - Answers✔Developed the first antiviral drug
Quiz 10:
Fascarnet is an antiviral drug that mimics pyrophosphate. Therefore, it inhibits viral replication
by binding to an inhibiting ___. - Answers✔DNA Polymerase
Quiz 10:
Which of the following describes the function of viral integrase inhibitors? - Answers✔Inhibit
incorporation of the viral DNA into the host genome
Quiz 10:
Viral entry inhibitors function by interfering with which of the following processes?
(Check all that apply) - Answers✔-Membrane fusion
-Genetic injection
-Endocytosis
NOT:
-Conjugation
Quiz 10:
Drug-target modification is a mechanism of viral resistance commonly seen with which of he
following drugs?
(Check all that apply) - Answers✔-Reverse transcriptase inhibitors
-Protease inhibitors
-Integrase inhibitors
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-Nucleoside analogs
Quiz 10:
NS5B is a drug that targets HCV RNA polymerase. The viral mechanism of resistance against
NS5B bears no fitness costs.
True/False - Answers✔FALSE
-any mechanism that changes enzymes, RNA or DNA polymerase has a fitness cost
Quiz 10:
Which of the following group is at the highest risk of contracting a subcutaneous mycosis? -
Answers✔Agricultural workers, miners, and gardeners
Quiz 10:
Which of the following statements are true about Candida auris?
(Select all that apply) - Answers✔-Associated with extended hospital stays
-Emerging MDR yeast
Quiz 10:
Fungi develop resistance to flucytosine using which of the following mechanisms? -
Answers✔Prevention of activation
Quiz 10:
Azoles represent one of the largest classes of antifungals. What is the mechanism of action of
azoles? - Answers✔Inhibition of sterol synthesis
*KNOW* Viral Characteristics - Answers✔Contain a *single* type of nucleic acid
-RNA or DNA
-NEVER both
Contain a protein coat that surrounds the nucleic acid
-sometimes the virus itself is *Enveloped*, enclosed by lipids, proteins, and carbohydrates
-Envelopes make viruses more susceptible to disinfectants
Non-enveloped Viruses
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-highly resistant to disinfectants
Multiply inside living cells by using the synthesizing machinery of the cell
-obligatory intracellular parasites
-absolutely *require* host cells to replicate
Causes the synthesis of specialized structures that can transfer the viral nucleic acid to other cells
*KNOW* How to kill something that does not live? - Answers✔Problem:
-not a lot of targets
-high replication rate = high mutation rate
-*Drives evolution of resistance*
Different shapes:
-*Polyhedral* (Polio)
-*Helical* (Ebola, Rabies)
-*Complex* (Bacteriophage)
-*Spherical* (Influenza)
*KNOW* Viral Replication -
Lytic Cycle - Answers✔*Lytic*
= viral replication results in death and lysis of host cells
Steps:
-attachment
-penetration
-synthesis/replication
-assembly
-release (through lysis, ready to infect cells)
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*Lysogenic*
= viral DNA gets incorporated into the host genome ad remains latent until activated
*KNOW* Lytic Virus Movie - Answers✔HIV is a typical retrovirus
= has an outer envelope
HIV has *2 copies of RNA* and an enzyme that is a *reverse transcriptase*
-will ultimately turn RNA into DNA
HIV itself directly infected *T-helper Cells*
-comes to cell surface, uses receptors/CD4 molecules on Th
-*CD4* is a surface receptor that binds to the envelope protein
-causes a conformational change and allows a *second receptor* to grab hold of the envelope
(*Chemokine Coreceptor 5/ CCR5*)
-Stalk of the envelope protein then pierces through the host cell membrane, eventually fusing the
2 viral and host membranes
-viral genetic material is injected into the cell, and envelope protein is left at cell surface
Virus has a *matrix* and a *capsid protein*
-they are digested when enter the cell
-releases viral enzymes and viral RNA
*Reverse transcriptase* takes the viral RNA, and using host nucleosides, converts the viral RNA
into ssDNA
-while doing this, makes random errors
(characteristic of Reverse Transcriptase = poor proofreading activities)
-ssDNA is again reverse transcribed into dsDNA
-*Integrase* (enzyme that also came in which virus) grabs dsDNA
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