Viruses Flashcards
What are viruses?
Not living organisms
Consist of a core of nucleic acid (DNA or RNA) and a protein coat or clasped.
Cannot replicate themselves, so are reliant on the host to do this for them.
Obligate parasites
Viruses are responsible for?
Disease in both plants and animals; they also infect bacteria.
What do they get from the host cell?
Energy and protein synthesis
Can they infect prokaryotes and eukaryotes?
Yes
Size of viruses?
10-300nm (1 billion nanometers in a m)
Many viruses are….
minor and self-limiting
How do viruses replicate?
Virus enters the cell of a suspected organism.
Viral nucleic acid acts as a code for the host cell to make more viral nucleic acid and protein coats that are assembled into new viruses.
Leave the cell and move to infect other cells. Perhaps being transmitted to a second individual.
Infection by virus sometimes…..
transforms a normal host cell into a cancer cell.
Viral shapes
Helical, icosahedral, complex
Example of a helical virus
Measles and rabies
Icosahedral virus example
Herpes simplex virus and polio virus
example of complex virus
bacteriophages and influenza
What is a bacteriophage?
viruses that infect bacteria (prokaryotic cells) e.g. coliphages infect E. Coli
What does influenza infect?
Eukaryotic Cells
Can you grow them on agar?
NO, but you can cell culture and viral PCR or RTPCR
