Virology Flashcards
Viruses are found on few materials.
True or false?
False - they’re found on or in just about every material on Earth
Viruses only infect mammals.
True or false?
False - they infect every form of life, even other viruses
What is the nucleic acid in viruses?
Either DNA or RNA either single stranded or double stranded
What is coating the virus?
Protein capsid coat - surrounds DNA or RNA to protect it
Could also have lipid membrane that surrounds the protein coat
How can a virus cause cancer in humans?
Viruses aggravate tissues and cause constant inflammation (HPV, HBV, HCV) and chronic infection with a virus can cause cancer at a site of persistent infection
What is meant by saying that viruses are obligate parasites?
They require an organisms for their propogation and are otherwise inert.
What is the simplest definition of a virus?
A small bundle of information that reprograms a cell to make more of itself.
What is the size range of viruses?
30nm to 300nm
What factors are used to classify viruses?
Size
Nucleic acid
Coating
What does protein do on a virus?
Coat the virus, aiding in entry and initiation of replication
What are viruses made of?
Protein
Virus genome
Lipids (sometimes, lipid membrane coat from host cell)
Small cofactors (in some)
Virion
Infectious particle oustide of cells composed of nucleic acid, protein capside and possibly an envelope. Can be extracellular or intracellular.
Most viruses have proteins that _____ host cells and immunity
Alter
Is the nucleic acid in viruses composed of a single fragment or multiple fragments?
It can be either - for example, influenza A virus’s genome has 8 RNA segments
The more ______ the eukaryotic genome, the easier it is to design therapeutic interventions
Unlike
Where do viruses bind on host cells for entry?
To receptors on the host cell’s surface. This allows either the whole virus to enter or allows the virus genome to enter.
What are the 5 basic types of viral symmetry?
Are naked viruses more or less stable than encapuslated viruses?
More stable in environment
What are the DNA viruses?
Herpes
Hepadna
Adeno
Anello
Papova
Parvo
Pox
Arboviruses are transmitted by _____
Arthropods (mosquitoes)
Naked (No lipid envelope) viruses are transmitted via ________
Fecal oral route
Enveloped viruses are sensitive to temperature and humidity changes.
True or false?
True
What is tropism?
Entry occurs via virus-receptor interactions
What is permissiveness?
Entry and replication of virus –> just because a virus enters the cell does not mean the internal cellular environment will allow for replication, need to differentiate between entry and entry + replication (permissiveness)
Describe viral replication.
The diseases caused by the virus is dependent on a virus’s ________
Tropism
What are viral epitopes?
Antigens on the surface of the virus that differ between strains or variants that are recognized by our antibodies
What are the different serological methods for detecting viruses?
Neutralization - patient antibodies bind to antigen to neutralize antigen
Antigen capture - put antidbody for antigen on plate, run serum over plate, design antibody with probe that binds to antigen (measures amount of antigen in patient)
Indirect ELISA - put antigen on plate, run patient serum over plate, antibodies will bind to antigen, design probe antibody for patient antibody to detect levels of patient antibody
Detect patient antibodies directly - put antibody for patient’s antibody on plate, run serum over plate, design antibody with probe for patient’s antibody –> detect levels of antibody
Why are there so few antiviral drugs?
Because viruses use an organisms enzymes to replicate so you can’t target the host’s enzymes or there will be terrible side effects. As such, most antivirals target virus specific proteins.
What is a modified live vaccine?
One where a small amount of the virus is allowed to replicate in the host and produces mild clinical signs. They contain live organisms and may cause disease in stressed hosts or if given via the wrong route.
What is a killed inactivated vaccine?
Either the whole pathogen or just part of it that is totally inactive
What are some examples of novel vaccines?
Recombinant protein vaccines (make protein from virus, only produces humoral response, high cost)
Subunit vaccines
Toxoid vaccines
Conjugate vaccines
Describe the process of action of a live attenuated virus.
What are some examples of viruses with dsDNA?
With ssDNA?
With dsRNA?
With ssRNA?
HPV, EBV, HSV
Polio, common cold
Rotavirus
Influenza, measles, ebola
