Viruses Flashcards
What is the protein layer in a virus called?
Capsid
What is the host range?
The type of cell or organism a virus is able to infect.
What are virions?
Inert viral particles outside of a host cells.
What are the two basic shapes capsids come in?
Helical and Icosahedral.
What does a helical capsid look like?
Rod or thread-like.
What does icosahedral capsid look like?
20 equilateral triangular sides.
What are the 2 classifications of viral infections?
Acute and Persistent.
In acute infections how fast do the viruses replicate?
Rapidly.
How detectable can viruses be in persistent infections?
They can be detected for a long time usually years.
What are the 3 types of persistent infections?
- Chronic
- Latent
- Slow
What is antigenic drift?
Accumulation of mutations in HA and NA genes which code for surface proteins (antigens) which are recognized by our immune system.
Influenza viruses are what type of infection?
Acute
HIV infections are what type of persistent infection?
Chronic
What are anti-retro viral drugs?
Drugs that target different aspects of viral replication.
8 different herpes viruses all cause what type of persistent infection?
Latent infections
What is a virus?
Nucleic acid surrounded by a protein.
What are 4 ways you can classify viruses?
- DNA or RNA
- Host range
- Virion morphology
- Genome type
What is the lysogenic cycle?
- Viral genome is integrated into host genome.
- The integration leads to prophage.
- Exits the chromosome, viral genes are expressed
What is the lytic cycle?
- Viruses attached to cell wall.
- Viral DNA penetrates cell.
- Viral DNA synthesizes in host cell.
- Eventually exploded killing host cell. Assembles inside
- Lysis of the cell are released.
What are the 4 different types of vaccines?
- Live attenuated vaccine- contains a live form of the virus that has been weakened.
- Genetic vaccine- delivers instructions in the form of mRNA to make proteins for the immune system to respond to.
- Inactivated virus vaccine- contains a virus that was killed using chemicals or heat.
- Viral vector vaccine- contains a viral vector that delivers genetic material that can be transcribed by host cell.
What are 4 human viral infections?
- HIV/AIDS
- Flu
- HPV
4 Herpes
