HIV Flashcards
What does HIV stand for?
Human immunodeficiency virus
It also leads to acquired immune deficiency syndrome (AIDS)
Describe the structure of HIV.
On the outside is a lipid envelope, embedded are attachment proteins. Inside the envelope is a protein layer called the capsid which enclosed two strands of RNA.
It also includes enzymes including reverse transcriptase.
What does reverse transcriptase do?
Catalysed the production of DNA and RNA- the reverse action is carried out by transcriptase.
What group of viruses does HIV belong to?
Retroviruses.
How does HIV replicate?
A protein of HIV binds to a protein CD4, most commonly on t helper cells.
The protein capsid fuses with the membrane and RNA enters the cell.
Reverse transcriptase converts the virus’s RNA To DNA
DNA is moved into cell’s nucleus and inserted into its DNA
Protein synthesis (replication)
The HIV particles break away with its membrane that surrounds them with lipid membrane.
How does HIV cause AIDS?
Without a sufficient number of helper T cells the immune system cannot stimulate B cells to produce antibodies or the cytotoxic T cells. Memory cells may be infected and destroyed and so the body is unable to produce and adequate immune response.
What does ELISA stand for?
Enzyme linked immunosorbant assay
How does ELISA work?
It uses antibodies to detect the presence on a protein in a sample and also the quantity. The antibody is specific to the antigen we are detecting. Add second antibody that binds to the first.
Why are antibiotics are ineffective against vita diseases like AIDS?
They cannot cause them to burst as their cell walls are made of murein which is a tough material and isn’t easily stretched. (Bacteria) some antibiotics inhibit enzymes needed for protein synthesis which then weakens it and causes it to burst.
Viruses lack their own metabolic pathways and cell structures and so the antibiotics cannot disrupt them and as they are within host cells they cannot be reached.
