Micro-organisms: Viruses Flashcards
What does it mean for a virus to be ‘obligate’?
An organism that fails to reproduce without exploiting a suitable host.
What is important about viral components during replication?
They must be able to self assemble.
What is a nucleocapsid?
Protein cage that helps form the viral particle genome contained within a protein capsule
What is a virion?
The infective viral particle.
For non-enveloped viruses this is the nucleocapsid; for enveloped viruses, this is the nucleocapsid and the envelope.
What does ‘H’ stand for with regard to viral naming?
Hemagglutinin receptor recognition on host cell
What are the characteristics of norovirus?
Non-enveloped (naked)
Self-limiting
What is important to note about naked viruses in comparison to enveloped ones?
They are much more stable in the face of environmental stress (e.g. gut, poor water treatment) than enveloped viruses.
Spread more easily
What is important to note about enveloped viruses in comparison to naked ones?
Must stay wet to remain infectious
Can spread via budding rather than cell lysis
How are different viruses grouped?
Single stranded Double stranded DNA RNA DNA and RNA
What are retroviruses?
Single stranded RNA viruses
What are hepadnaviruses?
Double stranded DNA viruses
What classes of proteins do the viral genomes code for?
Proteins for the future viral particles
Enzymes for genome replication
Proteins to interfere with host response
What is the site of viral entry into a host cell?
Site formed by the receptor and co-receptor
What are examples of -strand RNA viruses?
Influenza Mumps Measles Rabies Ebola
What are examples of double stranded RNA viruses?
Rotavirus