Viruses Flashcards
The two common types of DNA viruses are…
Phage T4 (virulent) & Lambda (temperate)
Virulent phage follow a _________ pathway, resulting in the ________ of the cell.
lytic; lysing
Temperate phage can follow either a _________ pathway or a _________ pathway (which results in a period of ___________)
lytic; lysogenic; dormancy
Resources plentiful: ________
Resources scarce: _________
lytic; lysogenic
Cells affected by phage in lysogeny that were permanently altered and are now life threatening diseases:
- Scarlett fever
- Diphtheria
- Botulism
A phage in lysogeny is sometimes called a …
Prophage
DNA polymerases…
make DNA
RNA polymerases…..
(with primase) make RNA
What RNA viruses need which is either brought along with them or immediately synthesized:
Replicase/Viral RNA Pol/Viral Replicase which is an RNA dependent RNA synthesizing enzyme
Three main flavors of RNA viruses
- (+) sense strand
- (-) sense strand
- Retroviruses
Nucleid acid synthesis, whether in the living or viral world, produced an ________________,_____________ molecule.
antiparallel, complementary
Components of HIV
Viral protein, protease, integrase, receptor-binding glyctproteins, viral RNA, reverse transcriptase
Reverse transcriptase
- RNA-dependent, DNA-synthesizing enzyme
- Degrades RNA component of RNA-DNA hybrid
- DNA-dependent, DNA-synthesizing enzyme (?)
HIV has very limited range of host cell specificity…
…host cell must display CD4 molecule and have a co-receptor (chemokine family)
Example of cells that display CD4 molecule and co-receptor
T-cells in our immune system
Molecule that can patch HIV into the host cell genome
Integrase is the tool HIV uses
Integrase has an NLS and so….
When we non covalently attach it only the viral DNA, it can go right in
How many bases are in the HIV genome?
9000
HIV does not proofread and there is 1 mistake every 2000 base pairs so…
…changes about 4 times every time it gets replicated which makes it difficult to develop a resistant drug
Viruses the enter via _________ use the drop in pH at the formation of the ___________ to trigger a conformation and escape into the cell.
endocytosis; early endosome
