Viruses Flashcards
What are viruses classified as?
Infectious particles
Rather than organisms
How do viruses multiply?
By invading a specific host cell
Must instruct the genetic and metabolic machinery of the host cell
What types of cells can viruses infect?
- Bacteria
- Algae
- Fungi
- Protozoa
- Plants
- Animals
What are the main components of a virus?
- External coating (capsid)
- Core containing nucleic acids
Name two types of DNA viruses.
- HSV (Herpes Simplex Virus)
- HBV (Hepatitis B Virus)
Name two types of RNA viruses.
- Influenza
- Rabies
What is the definition of a retrovirus?
A virus that uses RNA as its genetic material and reverse transcriptase to replicate
Example: HIV
What is a virion?
Fully formed virus able to establish infection in a host
What are the stages of viral replication?
- Adsorption
- Penetration
- Uncoating
- Synthesis
- Maturation
- Release
True or False: Viruses can be treated with antibiotics.
False
Antibiotics are ineffective against viral infections
What was the first anti-herpes drug released?
Vidarabine
Released in 1977 and highly toxic
What is the mechanism of action of Acyclovir?
When virus mistakes Acyclovir for dGTP, chain termination is irreversible
What are the indications for Acyclovir?
- HSV1
- HSV2
- VZV infections
What is the role of interferon (IFN)?
Used in preventing and treating viral infections
What are the main types of human hemagglutinin?
- H1
- H2
- H3
What is the FDA-approved antiviral for early treatment of flu?
Oseltamivir phosphate (Tamiflu)
What does COVID-19 severity data suggest about critical patients?
49% deaths among 2,087 critically ill patients
Data was adapted from Zhang 2020
What are the two main mechanisms of action for antiviral treatments for COVID-19?
- Chain terminators (e.g., Remdesivir)
- Block COVID entry into cells (e.g., monoclonal antibodies)
Fill in the blank: Viruses are _______ intracellular parasites.
Obligate
What suffix is used for virus families?
-viridae
What suffix is used for virus genera?
-virus
What are naked viruses?
Viruses that consist only of a nucleocapsid
What is the primary method to control viral infections?
Vaccination
Few antiviral drugs are available
List three examples of viral infections that commonly do not result in hospitalization.
- Colds
- Chickenpox
- Influenza