Study guide

 

Viruses Study Guide

Viruses (parts 1 & 2; I highlighted what was relevant in Week 6)

Virus	Prion	Obligatory intracellular pathogen	Virion	Capsid	Envelop virus
DNA virus	RNA virus	----	Non-enveloped virus	Spike	Bacteriophage
Lytic cycle	Lysogenic cycle	Multiplication cycle		Eclipse period	Assembly
Release	Recombination	Latent virus	Phage/lysogenic conversion	Induction	---
Animal viruses	Retrovirus	Reverse transcriptase	Integrase	Provirus	SARS-CoV-2
COVID-19	Spike	ACE2	Variants	Influenza A virus	Hemagglutinin
Neuraminidase	Antigenic shift	Antigenic Drift	Oncogene	Tumor suppressor	Cancer
Oncogenic virus	HPV	Prion

 You can refer to the lectures and pre-class activities (videos & textbook chapters linked there). 

You should be able to explain in your own words (yellow stuff is mostly covered in pre-class of this week)

• What does it mean for a virus to be an obligate intracellular parasite?
• How is the host range of a virus determined?
• Differentiate bacteriophages from animal viruses
• How big is a viral genome compared to a bacterial genome? What kind of genes are found in a viral genome?
• Compare and contrast a capsid from a viral envelope. Do all viruses have envelops? What about capsids?
• During viral replication, what two types of molecules must the virus make? How and where do viruses replicate? What do viruses provide & what does the host cell provide? What is the fate of the virus-infected host cell?
• Describe the stages and what happens in each stage of the lysogenic cycle of bacteriophage λ.
• What is phage conversion & when does it happen?
• How could bacteriophages be used to treat bacterial infections in humans?
• Describe how attachment in animal viruses to the host cell determines the host range, and the type of cell that is infected. Why are the adhesins on a virus considered a virulence factor? Describe the process of entry of animal viruses to the host cell and release from the host cell.
• How is the genome of DNA viruses replicated? What enzymes are used & what is their origin (host or viral)?
  • How are structural proteins for DNA viruses made and assembled? What enzymes are used & what is their origin (host or viral)?
• List the four classes of RNA viruses & describe their genomes.
  • What is a sense (+) strand of RNA? What about antisense (-) strand of RNA?
  • What is the function of RNA-dependent RNA polymerase and is it viral or host?
    • How is a DNA-dependent RNA polymerase different?
  • Why do RNA viruses tend to accumulate more mutations than DNA viruses? Why does this make RNA viruses harder to treat?
  • Describe how the genomes for the following types of viruses are copied & how the structural proteins are made/assembled. Name the enzymes involved and whether they are host or viral:
    • ssRNA viruses with a + strand
    • ssRNA viruses with a – strand
    • ds RNA viruses
    • retrovirus
  • Depending on the viral structure and type (genetic material), can you identify if an antiviral target will work on the virus you are interested in?
    • Why don't antivirals work on bacteria? Why don't antibacterials work on viruses? Why should neither antibacterials nor antivirals target us (humans) in theory?
  • What is a retrovirus? What is the function of the different components of a retrovirus?
    • What is the biosynthesis of retroviruses (use terms: reverse transcriptase, viral integrase, provirus)?
    • How does a retrovirus cause a latent viral infection and why are these hard to treat?
  • Describe the structure and genetic material of SARS-CoV-2. What are the portals of entry & exit?
    • Describe the interaction b/w the spike protein & ACE2. Where are each of these proteins found? Why is this interaction important?
  • Explain the origin of the variants of SARS-CoV-2. How and why have these variants become more or less prevalent over time?
  • Describe the structure and type of influenza A virus. What are the portals of entry/exit?
    • What are the two major surface proteins in the envelope of influenza A? How many different types are there? How do they determine severity fo the influenza virus?
    • Why do you need to get a new flu shot every year?
    • Why does the immune system have some memory for seasonal flu but not when an antigenic shift happens.
  • Differentiate antigenic drift from antigenic shift. Why do antigenic shifts cause more severe diseases & pandemics?
  • Regarding the Varicella-Zoster virus:
    
    • Distinguish between varicella and herpes zoster.
• Describe how viruses are involved in cancer.

• What is a prion and what is the outcome of a prion infection? 
  
  • Discuss the model for prion infectivity we discussed in class. Be sure to state how a normal cellular protein can be converted to an infectious prion form.
  • Didn't get to this stuff this quarter for Unit 2!!!! (crossed out)

 

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