1r Tema Flashcards
(30 cards)
Where a virus can be found?
Virus can be found anywhere: in soil, water and air
What type of living being can they infect?
they can infect any type of living being
What is a virome?
it is a viral particle living insede our body,there are 10^15
Does every virus affect us?
There’s many of them that doesn’t affect us
Can viruses be beneficial to the host?
Yes, an exemple is a plant that thanks to a virus wich is infecting a fungus that livs in the plant is able to grow in vety extrem temperatures.
How are phages seen in a negative stainning?
Phages are seen in color white, whereas the background is seen dark (due to the heavy metals)
How are phages seen in a positive stainning?
Phages are seen in a color black, whereas the background is seen kinf of white.
What is an X-ray diffraction?
When the virus is cristalized, we have this kinf of structure in wich it can be seen the proteines crystalised
How was the tobacco mosaic experminet carry ou?
First, extraction of sap froma a tobacco plant hit the disease, the the sap was passes through a porcelain filter, then, this sap was rubbed om a healthy tobacco plant. Martinus Beijerinck, “contagium vivum fluidum”
What is a virus?
A virus is a genetic entity that cannot replicate independently of a living cell, uses host cellular machinery to multiply.
Where can we found the genoimic matirial of the virus?
Inside the capsid
What are the main components of a virus?
Nucleic acid and proteins
Wich types of morphology are?
Helical, iscosahedral and mixed symmetry
Ho do they get the envelope from the host cell?
They can take the exterior membrane, and sometimes they can take the nucleic membrane
What is homeostasis?
It’s the ability to keep a constant chemical composition inside, the equilibrium is essential. It’s the tendency towards a relatively stable equilibrium between independent elements, specially as maintained by physiological processes.
Are all viral mRNA translated by the host ribosomes?
Yes, they parasite the host protein synthesis machinery. Viruses can’t produce ribosomes.
IS a virus the same as a viral particle?
It’s not the same. A viral particle is the extracellular form of a virus, meanwhile a virus is the intracellular form
Do plant viruses require a receptor?
plant viruses do not require, in general, a receptor
What is a lytic infection?
Virus recongnises the receptor, infection, productiopn of lots of viral particles or virions, finmallym lysis of the host cell. Equivalent to the lytic cycle in bacteriophages.
What is a latent infection?
The virus enters the host cell and remains ther indefinetly. Equivalent to lisogenic cycle in bacteriophages
What is a persisten infection?
The virus produces very few viral particles. When the virions exit the host cell, the cell doesn’t die. This is because it’s an enveloped virus
Transformation
When a virus infects the host cell transforming it into a tumoral cell
Cell fusion
Enveloped viruses usually have fusion proteins. These fusion proteins allow the fusion of the membrane of the host cell and the membrane of the enveloped virus.
Our genome is formed
by retroviral DNA sequence
