lecture 19 Flashcards
1
Q
Viruses
A
- Acellular
- most are composed only of nucleic acids and some proteins
- consist of a central core of DNA and RNA surrounded by a capsid of proteins
2
Q
Why can’t viruses do?
A
- Regulate transport of materials into and out of themselves
- perform any metabolic functions
3
Q
Virus: obligate intracellular parasites
A
- They use the host cell’s DNA replication and protein synthesis machinery to reproduce themselves
4
Q
Phage (bacteriophage)
A
- Reproduces immediately and kills the host cell
5
Q
lytic cycle
A
cell bursts and releases progeny viruses
6
Q
Lysogenic cycle
A
Postpones reproduction by integrating its nuclei acids into the host cell’s genome
7
Q
Retrovirus (HIV)
A
- Reverse transcriptase
- facilitates RNA
- directed DNA synthesis
8
Q
DNA provirus
A
- produced
- integrated permanently into the host’s genome
9
Q
What happens when proviral DNA is activated?
A
New virions are produced
10
Q
Reserve transcriptase
A
RNA into DNA
11
Q
Lyric viruses
A
Polio, rabies, measles, colds
12
Q
What phase do viruses have?
A
- Lyric phases
- some have Lysogenic phase
13
Q
EBV
A
- Lystic leads to mono
-Lysogenic leads to lymphoma
14
Q
HPV
A
- Lytic lead to genital warts
- Lysogenic can lead to cervical cancer
15
Q
Herpes
A
Lytic and latent Lysogenic properties
16
Q
HPV
A
- Virus known to cause cancer
- HPV vaccine prevents infection by the virus and therefore cancer
