Lecture 14

Question 1

Basic Virus Structure

Answer 1

• bacteria have an immune-like system called CRISPR-Cas to battle bacteriophages attacks

Question 2

Virus Classification

Answer 2

• Many families and subtypes

- Baltimore classification is a common on: categorizes viruses based on genome type and replication method

Question 3

Are Viruses Cells? What are they?

Answer 3

• NOT CELLS
• macromolecular packages function and reproduce ONLY w/in living cells
• very small
• outside cells, they are VIRION: made of small DNA & RNA amounts that encode hundreds of genes w/ protein capsule called CASPID

Question 4

Infection Types

Answer 4

Lytic: production of virus particles ruptures and kills cells
Non-Lytic: viral DNA instead in host genome- PROVIRUS
infected cells can survive but functions will be altered

Question 5

Host Range

Answer 5

NARROW: human cold/influenza- virus infects epithelial cells of respiratory system
WIDE: rabies- infect humans, dogs, foxes, bats and racoons

Question 6

How do virus infect cells?

Answer 6

• once in cell- virus highjacks cellular machinery to synthesize nucleic acids and proteins to assemble new viruses to infect more cells

Question 7

Basic structures of viruses

Answer 7

1) a nucleic acid genome

2) protein capsid that covers the genome.

Question 8

Main factor that determines what cell type a virus can infect

Answer 8

surface expression of a specific surface protein.