Viruses - Structure Flashcards
Viruses are non-cellular - what does this mean?
No nucleus
No cytoplasm
No organelles
What are viruses?
Small parasite/particle/agents
Viruses are obligate intracellular parasites - what does this mean?
They cannot reproduce outside of the host
How do viruses produce proteins and nucleic acids needed to reproduce?
- They are inert outside of host
- So they utilise host cell processes to produce proteins and nucleic acid needed to reproduce
What does a virion (entire particle) consist of?
Nucleic acids and protein capsule.
What can be used for classification of viruses?
RNA or DNA with protein structure
What standard organelles do viruses lack?
Mitochondria
Chloroplasts
What is differential diagnosis?
Possible conditions that share the same symptoms - could have many diagnoses.
What are the different ways we can classify viruses?
1) Nature of genome
2) Presence of an envelope
3) Morphology
4) Genome configuration
5) Genome size
6) Virion size
What are examples of poxviridae?
1) Bovine papular stomatitis virus - not in UK
2) Orf in sheep and goats
What are examples of Herpesviridae?
1) Aujeszkys disease in pigs - eradicated from UK but could return
2) Bovine infectious rhinotracheitis (IBR) = common
What’s in the normal cat vaccine?
- Feline herpes virus
- Feline calicivirus
- Feline infectious enteritis
- Feline leukaemia virus
What are examples of Parvoviridae?
- Parvovirus in dogs
- Feline panleukopenia in cats
What are examples of paramyxoviridae?
- Rinderpest = ruminants
- Newcastle disease = major poultry disease (vaccination)
- Canine distemper in dogs (vaccination)
What’s an example of coronaviridae?
- Feline enteric coronavirus
- Feline infectious peritonitis (FIP) = fatal
