Virus Review Flashcards
What does the word virus mean?
Virus means poison
List and breifly describe the criteria used to classify viruses?
Classification is based mode of replication, the type of nucleic acid they contain(RNA or DNA), their shape, size, what the host is, and by the presence or absence of an envelope.
What is a prophage?
Integrated viral DNA (vDNA) in the host cells DNA
How does a bacteriophage inject it’s DNA into the host cell?
The spike Pierces the cell membrane of the host cell and the tail tube pumps DNA from the head to the host cell
How does a Vaccine protect us from some viral attacks?
You get injected with a dead version of the virus, the b lymphocytes of the person injected produce antibodies specific to each antigen, then the viruses are deactivated by the antibodies then cleaned up by phagocytize cells such as macrophages, specialized T cells store the blueprints for each antibody produced for future use.
How does a virus take over or utilize the host cell?
Once it attacks it ejects the genome into the host cell and creates new bacteriophages that burst out and continue the cycle
During what cycle does a bacteriophage become latent and what does this mean?
The lysogenic cycle, latent means inactive or dormant and does not make new virons
What are viruses made of?
Genome (nucleic acids) surrounded by a protein coat
How does the human body prevent the entrance of viruses and other pathogens?
Using primary, secondary and tertiary lines of defence.
In the Primary Line of defense, what protects our body?
Physical barriers (skin and other lining tissues).
Sweat, olis and waxes.
Tears and saliva.
Mucus membrane of the nose, mouth, gut and lungs
how does the Secondary line of defense protect our bodies from viruses?
Our bodies produces white blood cells that travel through blood into tissue cells, then surrounds and engulfs microbes (viruses and bacteria).
What are 2 ways in the which white blood cells are used by the body for defence against microorganisms
They move through blood into tissue cells and surrounds and engulfs microbes, this is phagocytosis. The white cells produce antigen specific proteins, called antibodies, these antibodies attach to the antigen in a lock and key fashion and disable it.
What is a difference between a T-4 bacteriophage and a HIV or flu virus?
Bacteriophages are double stranded while HIV virus is usually singular stranded
How does the Tertiary line of defense protect our bodies?
B-lymphocytes (specialized WBC) produce antibodies that attach to an antigen in a lock and key fashion that disables it.
What are Interferons
Small proteins produced by viral infected cells. they help other cells resist viral infection.
