Viruses Part 2 Flashcards
Three cell lines can be used in cell cultures what are they?
Primary cell lines
Diploid cell lines
Continuous cell lines
Primary cell lines
Derived from tissues by enzymes
Generally die after a couple of generations
Diploid cell lines
Derived form human embryos
Multiply for about 50-100 generations and then die
Continuous cell lines
Immortal lines are derived from transformed or cancerous cells
Can multiply indefinitely in clutter and are immortal
These are commonly use in propagation of viruses
What are HeLa cells? Tell the history.
Immortal cell line used for cancer research.
The only human cell line able to reproduce indefinitely.
Taken from a dead female cancer patient, named Henrietta Lacks in 1951 without permission.
Where do viruses ONLY replicate?
Inside the cell
What happens when viruses invade host cells?
Controls metabolic and replication “machinery”
The cell will now primarily make viral proteins and nucleic acid for new viral particles.
3 stages of host interactions/cycles
Lytic cycle
Lysogenic or latent cycle
Transforming interaction
Lytic cycle
Host cell is lysed after viral replication
Lysogenic or latent cycle
Host cell stays alive after replication
Viral genome is integrated into host’s genome
Transforming interaction
Viral genome is integrated into host’s genome
Integration alters host cell growth and morphology
Cancer-like cell
Two cancer-like cells
Epstein-Barr and HPV
The viral replication cycle of animal viruses
1 attachment or absorption
2 penetration or entry
3 uncoating
4 biosynthesis
5 maturation or assembly
6 release
the step with the major difference between RNA and DNA viruses.
Biosynthesis
Where and how proteins are made
Lysogenic steps
1 attachment or absorption
2 penetration or entry
3 uncoating
4 INTEGRATING INTO THE CELL
5 biosynthesis
6 maturation or assembly
7 release
Viral particle attaches to host cell via specific _____
Receptors
On the surface of the host cell
Some proteins and glycoproteins on host cell membrane can function as ____
Receptors for some viruses
Viral particle have attachment sites made of ___ or fibers that bind these receptors.
Spikes
naked viruses
Neucleocapsid
Enveloped viruses
Envelope on spikes
Can a virus effect all cell types?
No, they can only effect a few or one cell type but NOT ALL.
Are there many antivirals to block the attachment step?
No
What is the most difficult step of the replication cycle?
Penetration
In the penetration stage, what is happening?
A viral nucleic acid is inserted into the host cell
What are the two ways of entering a cell for a virus?
Receptor mediated endocytosis
Fission of viral envelope and plasma membrane
After fusion of the viral envelope and plasma membrane, what happens?
The viral nucleocapsid enters the cytoplasm
Nucelocapsid is made up of
Nucleic acid with capisid
What type of virus can enter a cell via endocytosis?
Naked and enveloped
What is the “coat”?
Capsid of the virus
Uncoating is the
Separation of nucleic acid from the protein capsid coat
____ have attachment points and enters through endocytosis.
Naked
