Virology Flashcards
1
Q
what are the general characteristics to viruses?
A
- “non living” particles
- capsid and genome
- subcellular: smaller than cell
- intracellular: replicate within host cell, and use cell’s resources for own life cycle
- parasites: benefit from and harm host cells
2
Q
what do viruses NOT do?
A
- do NOT carry out metabolic processes
- do NOT reproduce independently of host cells
- do NOT contain nucleus, cytoplasm, and organelles
3
Q
describe viral structure
A
- very small
- genetic material
(1) DNA or RNA
(2) SS or DS
(3) linear, segmented, circular
(4) 2-1000 + genes
4
Q
can viral populations undergo evolution?
A
yes - constantly evolving
5
Q
capsid
A
- protein coat surrounding genome - in all viruses
- made up of capsomeres: capsid proteins
- determine morphology, involved in attachment to host cell
6
Q
envelopes
A
- phospholipid bilayer surrounding capsid - only some viruses
- acquired from host
- contains host and virus proteins
7
Q
what is the general cycle of replication?
A
- bind to host cell
- genome enters cell
- genome replication and gene expression
- assembly
- exit
8
Q
lytic cycle
A
- essentially the same as the general cycle
- host cell cell destroyes/lyses when viruses exit
- horizontal transmission
- the flu
- the spread of a virus from one thing to another
9
Q
lysogenic cycle
A
- viral genome gets replicated, but host cell is NOT destroyed
- vertical transmission
- Huntington’s disease
- transmission of virus from parent to offspring
10
Q
what are the phage types?
A
temperate phage and virulent phage
11
Q
temperate phage
A
capable of lytic and lysogenic replication (e.g. Phage Lambda)
12
Q
virulent phage
A
capable of lytic replication only (e.g. Phage T4)
13
Q
in what environmental conditions would lytic versus lysogenic replication be more favorable
A
- if there’s a lot of resources in the environment (lysogenic)
- in bad conditions (lack of resources) (lytic)
