Virology 1: Intro to Veterinary Virology Flashcards
Describe the characteristics unique to viruses
smallest infectious particles
range from 18-300 nm
consist of RNA OR DNA and proteins with or without lipid membrane coat
lack independent metabolic system
require host cell for replication
consist of intracellular repro cycle and an extracellular transmissive cycle
What is the typical range in size for a virus
18-300 nm
Do viruses consist or RNA or DNA
EITHER OR - NEVER BOTH
What do viruses lack
independent metabolic system
What do viruses require for replication
host cell
Why are viruses considered to be true parasites
require host cell for replication
Which microorganims multiplies by binary fission: unicellular or viruses
unicellular
What are prions
Proteins that exist normally in the cells but have ability to misfold and cause disease
Prions that exist normally in the body are ____ and prions that are abnormal and have conformational aberration are _____
Normal = PrPc
Abnormal = PrPsc
What is the difference between a virus and a prion?
a virus is an infectious particle that contains a nucleic acid particle covered by a protein core
a prion is a simpler infectious particle that is made up of only proteins
What is the difference between an enveloped virus and a non-enveloped virus in terms of survival and pathogenesis
enveloped viruses have short survival in environment, and labile, and are easier to inactivate whereas non-enveloped viruses are more resistance, and have longer survival in environment
Enveloped viruses bud through infected cells leading to chronic/persistent infections whereas non-enveloped viruses have lytic infection and are often associated with acute disease
Which type of virus is associated with seasonal disease?
enveloped viruses
Which type of virus lasts longer in the environment?
non-enveloped virus
Which type of virus is easier to inactivate?
enveloped virus
Which type of virus buds through infected cells and is chronic or more persistent?
enveloped virus
Which type of virus has only the nucelocapsid protein and is considered “naked”?
non-enveloped
What is the correct taxonomy of viruses?
order, family, genera, species
What is the nomenclature of virus order?
virales
What is the nomenclature of virus family?
viridae
What is the correct nomenclature of virus genera?
virus
What is the correct nomenclature of virus species?
Strain
What taxonomy would arteriviridae be considered under?
family
What taxonomy would nidiovirales be considered under?
order
What taxonomy would arterivirus be considered under?
genera
What taxonomy would equine arteritis virus be considered under?
species
What are the building blocks of non-enveloped viruses?
Protein subunit
Structure unit
Capsomer
Capsid (coat or shell)
nucleocapsid
What are the building blocks of enveloped viruses?
Protein subunit
Structure unit
Capsomer
Capsid (coat or shell)
nucleocapsid
+
ENVELOPE
What does the envelope of a virus contain
peplomer/spike carbs, glycoproteins, and phospholipids
What are structural proteins
virion proteins
containing:
capsid/nucleocapsid: protecting genome
envelope protein (spike, matrix), ligands( VAPs)
What are non-structural proteins
enzymes, replication, regulatory proteins
-polymerases/transcriptases
-reverse transcriptase
-integrase
What does the non-structural protein polymerase do?
turns dsDNA/dsRNA to mRNA
What does the non-structural protein reverse transcriptase do?
retroviruses from RNA to DNA
What does the non-structural protein integrase do?
integrates proviral DNA of retroviruses into host genome
Is DNA double or single stranded? What about RNA?
DNA = ds
RNA = ss
What is the most common symmetry for DNA? RNA?
DNA = icosahedral
RNA = helical
What is the relative size of DNA to RNA?
DNA = bigger than RNA
What symmetry do RNA and enveloped viruses have?
Helical
Most DNA is icosahedral but ______ is an outlier and has complex symmetry
Poxvirus
What are the 2 life cycles of viruses?
Extracellular (Transmissive, inert)
Intracellular (reproductive)
What are unconventional viruses (subviral particles)?
extremely simple, replicating agents, either nucleic acid or protein
What are viroids/virusoids?
Plant pathogens
Where do viroids replicate?
in the nucleus
Where do virusoids replicate?
in the cytoplasm
What are 2 types of subviral particles?
Viroids/virusoids
Prions
What are prions?
A small proteinaceous infecting particle with NO nucleic acid genome
What is unique about prions?
resistance to heat, UV, irradiation, and chemicals
What is the chemical composition of viruses
nucleic acids, proteins, carbs (glycoproteins), and lipids
