Cell Diversity and Viruses Flashcards
What is virion?
- Small amount of DNA or RNA that encodes genes
- Protein capsule called a capsid
Baltimore classification:
Categorizes viruses based on their type of genome and method of replication
Some types of viruses from lecture [5]:
1) Retroviruses
2) Hepadnaviral
3) Filoviruses
4) Adenoviruses
5) Bacteriophage
What is HIV
- Example of a retrovirus
- Inserts a copy of its genome into the DNA of host cell
Hepatitis B:
- Hepadnavirus family
- Affects liver and causes infection
Ebola virus:
- Filovirus family
- Encodes their genome in single stranded RNA
- Causes hemorrhagic fever
Adenoviruses:
- Causes respiratory illnesses and conjunctivitis
Bacteriophages:
-Infects and replicates within bacteria and archaea
Host ranges [2]:
1) Narrow (ex. influenza infects only epithelial cells of respiratory systems)
2) Wide (ex. rabies can infect a wide range of cells in lots of mammals)
Types of viral infections:
1) Lytic
2) Non-Lytic
What is a lytic infection?
Rapidly replicates inside a host cell until the cell ruptures and the virus can then infect other cells.
What is a non-lytic (integrative/lysogenic) infection?
Integrates into the host cells genome where it can remain dormant or cause persistent infections.
Virus lifecycle [5 steps]:
1) Attachment
2) Entry and formation of endosome
3) Uncoating–capsid is broken down releasing viral nucleic acid
4) Replication and protein synthesis
5) Assembly and release
How do RNA vaccines work?
They work by tricking the body’s cells into producing an antigen from an RNA template.
RNA viruses:
- Influenza, HIV, Zika, Ebola
- Less stable than DNA viruses
- Can be single or double stranded
