LECT 1 Qs Flashcards
What is a Virus?
Genetic element that replicates intracellularly and programs the synthesis of particles that transmit its genome from one cell to another
What is a bacterical virus called?
Bacteriophage (or just phage)
How much of Viruses are made up DNA/RNA?
1-50% is made up Nucleic acids
Can be either DNA or RNA
Expanded Definition of a Virus
- Small particle
- Genetic element moves from cell to cell
- Genes enclosed in some type of shell
- No energy metabolism or ribosomes
- Intracellular parasite (infects host)
What is a Naked Capsid Virus?
A virion with a just a protein coat over genetic material
What is a Enveloped Virus?
A virion with protein coat AND membrane/envelope over genetic material
What is the difference between cellular multiplication and viral multiplication?
Cellular: Divide exponentially (x^n)
Viral: Expands at a quicker rate as opposed simply dividing
What are host ranges?
The types of cells a virus can infect
Can viruses infect everything?
Generally only infect particular types of cells
The first steps of infection are…
Do all infections start with these steps?
- Adsorption (attachment to cell surface)
- Penetration (getting inside the cell) - sometimes uncoating
- Uncoating (protein shell is removed from nucleic acid)
Yes, they all start off the same way
What are the steps following during a Productive Response?
- Component production (making of the genome stuff)
- Assembly (encapsidation)
- Release
What are the two resulting fates after release of baby phages?
Cell death after lysis - lytic infection
Cell survival - chronic or persistent infection
What types of viruses causes lytic infections?
Cytocidal viruses
What types of viruses causes chronic infections?
Filamentus phages and retroviruses
What follows a Nonproductive Response?
What happens during that state?
Latent State
Virus persists within the host and does not lyse (lysogeny)
