Viruses and Prions Flashcards
1
Q
Name the 3 methods a virus uses to infect a host
A
- Lysis
- Fusion
- Endocytosis
2
Q
What is Endocytosis?
A
- when the virus attaches to and invaginates the cell through its membrane
3
Q
What is Lysis?
A
- Rupture of the cell wall
4
Q
What is fusion?
A
- The viruses membrane fuses with the host cell
5
Q
How can viruses be classified?
A
- RNA
- DNA
6
Q
Give an example of a RNA virus
A
Influenza
7
Q
Give an example of a DNA virus
A
Herpes simplex virus
8
Q
What are the 2 methods in which viruses reproduce?
A
- Lytic cycle
- Lysogenic cycle
9
Q
Describe the Lytic Cycle
A
- The phage DNA causes the cell to rupture and release the phages to allow them to attach to further host cells
10
Q
Describe the Lysogenic Cycle
A
- Phage DNA integrates into the bacterial chromosome (Prophage)
- The bacterium reproduces copying the prophage into the daughter cells
11
Q
Give 3 features of a prions structure
A
- They do not have a nucleic acid genome
- The infectious agent is a protein
- Known as spongiform encephalopathies
12
Q
How do prions cause infection?
A
- They cause irreversible conformational changes to the proteins in the brain which cause lesions and disease
13
Q
What are prions resistant to?
A
- Heat resistant
- UV resistant
14
Q
Name 3 diseases associated with prions
A
- Scrapie
- Bovine Spongiform Encephalopathy
- Creutzfeldt Jakob Disease
15
Q
What is scrapie?
A
- A neuro-degenitive disease found in sheep
