Describe a DNA virus?
Contains DNA which acts as a template for the manufacturing of new DNA and mRNA to make viral proteins.
E.g. bacteriophages including lambda phage which attacks e.coli
Describe RNA viruses?
Contain RNA and make new RNA from it, no DNA is made. E.g. tobacco mosaic virus and Ebola virus.
Describe retroviruses?
A special type of RNA virus. They contain RNA that directs the synthesis of the enzyme reverse transcription. This makes DNA versions of the RNA genome. This DNA is incorporated in the host cell and used to make more viral proteins and RNA genomes. E.g. human immunodeficiency virus (HIV).
What are the drugs used against viruses called?
Antivirals
How does a virus differ in structural features to a bacterium?
Viruses do not have a cytoplasm or ribosomes whereas bacteria have both. Viruses have a protein coat which is not found in bacteria. Viruses have a protein coat which is not found in bacteria.
What is the lytic cycle?
The viral genetic material replicates independently to host DNA. This genetic material takes over the hosts machinery and new viruses are made and host cell burst releasing the virus.
What is the lysogenic cycle?
The viral nucleic acid is incorporated into the host cell genetic material and spread through the host-cell reproduction.
What is the retrovirus cycle?
The RNA is translated to DNA by reverse transcriptase in the host cell. Viruses leave the cell by exocytosis. The host cell continues to make viruses and new ones infect other cells.
What are the main ways you can prevent the spread of a virus?
-protective equipment such as face masks, googles, gloves
-medical equipment sterilised
-careful hand washing
What are some ethical issues if a drug has not been fully trialled is to be used to treat an outbreak?
-severity of the disease
-availability of other treatments
-ongoing assessment of safety and efficacy
-effectiveness of disease control
