Viruses Flashcards
Size
smaller than bacteria
20-300 nano metres
Nucleic Acids
DNA and RNA
Are they living
not living themselves
require a host cell to multiplly inside
Capsid
protein coat
surrounds genetic material
Attachemnt Proteins
on the lipid envelope
allow the virus to identify and attach to a host cell
HIV
Human Immunodeficiency Virus
HIV enzyme
reverse transcriptase
Reverse Transcriptase
converts RNA to DNA
reverse of transcription
Retrovirus
group of RNA viruses which insert a DNA copy of their genome into the host cell inorer to replicate
HIV Infection
Virus enters the bloodstream
Attachment proteins bind to the cell surface protein CD4 on the T helper cell surface
RNA and Reverse Transcriptase of HIV enters T helper cell
Enzyme converts RNA to DNA
New DNA is taken to the nucleus and incorporated into the circular DNA
Cell makes mRNA from viral genes
Makes new viral proteins and RNA
mRNA moves to the ribosmes for viral protein synthesis
HIV particles burst out of the T helper cell
T helper cell surface membrane forms lipid evvelope
Dormancy
Where HIV just circulates in the blood and not the infection
Antibody Binding Assay
Add blood
HIV antibodies have a specific complementary shape to bind to the antigens
The plate is washed to remove any unbound antibodies
A second antibody is added to bind to the first
Second antibody has an enzyme attached
It is washed again to remove any unbound antibody
A colourless dye is added
Enzyme changes colour when added
HIV antibodies means
HIV present
AIDS
Acquired Immunodeficiency Syndrome
Do AIDS kill
They don’t kill themselves they make other pathogens do it through secondary AIDS related illnesses
