Topic 5 Flashcards
(40 cards)
Who founded viruses?
Dimitri inv…
Who showed yellow fever was a virues
Walter reed
Who coined the term plaque and found bacteriophages
Felix d’…
What are bacteriophages and what a good fact on them
There are viruses that eat bacteria , they are the most abundant on earth
Why are viruses not considered alive
They are not considered alive bc they need a host self to be able to replicate and they have no
Metabolism
What are viruses
They are a small subcellular partice that requires a host to replicate
Between pro and eukaryotes and viruses who is the smallest
Viruses
What is the structure of a virus (whats in a virus)
A virus can have either sigular or linear RNA OR DNA Genome
With a protein shell surrouding it called capsid
And same may have an envelope surrounding the capsids
Where can the viruses get its envelope
It can get it envelope from the host cells membrane , golgi app, ER or nucleus
What is a nucleocapsid
Its rhetorical Genome + capsid
What is the possivle size of virus
its can be 10 nano metres -100 nanometers
What are the three big virues exception
Mimivirus 400 nanomemteres ,pandroaviruses 1micro , mega viruses
How many shapes can capside comes as ?
Helical icoshedral or irregular like bacteriophages
There are 3 proteins are each icosohedreal face and there are 20 faces meaning there are 60 capsoemrec
What is the duty of a capsid,
To protect the rna or dna through processes
What are the 6 steps for viral replication
Adhere (stick to host cell)
Enter
Uncoat( release genome)
Synthesis (replicate genome)
Assembly( put together new viral particle)
Exit
For an animal cell what are the two ways a virus can enter
Endocytosis and membrane fusion
What are the steps for endocytosis for an unenvelope membrane ?
- Virusues attaches to cell receptors
- Endocytosis is initiated
- An endosomes forms with the virus inside
- The nucleocapsid enters the cytoplasm and release tbe genomes
What are the steps for membrane fusion of an enveloped virus
- Virus attaches to cell receptors
- A change in the attachement proteins let the receptor initiate membrane fuction
- The virus and evelops and plasma membrane of host cell fuses
- The nucleocapsid enters the cytoplasm and the genomes are released
What are the 4 steps for endocytosis of and envelopes virus?
- Virus attaches to cell receptor
- Endocytosis is initiated
- An endosomes forms with virus inside
- The low ph in the endosome initiates fusiin between the endosomes membrane and the virus and the nucleocapsid is released
What is need for a virus to enter a plant ?
Damage is needed to the plant tissue to open the cell wall
What are the steps for a bacteriophage to enter a bacterial cell
- Tail fibers attach to receptors
2.Change in tail fibers allow base of tail to get into contact with surface of host cell - Rearrangements of tail proteins allow the tube proteins to enter the cell wall through to the membrane
- When bacteriophage get in contact with the membrane , DNA IS RELEASED
What is the lytic cycle of bacterial replication
Its is when the viral enter , replicates and always ends up killing the host
What is the temperate page aka lysogenjc cycle
Where a bacteriophage enters and cell and stay untill conditions gets bad then kills the cell
Can either is a prophage or lytic
