Human Immunodeficiency Virus

Question 1

What is the structure of the Human Immunodeficiency Virus?

Answer 1

-Outer lipid envelope with attachment proteins embedded within it
-Protein layer within (Capsid) encloses two single strands of RNA and reverse transcriptase
-Reverse transcriptase can catalyse the production of DNA from RNA
-‘Retrovirus’

Question 2

How does the Human Immunodeficiency Virus replicate?

Answer 2

-HIV enters the body and circulates via the bloodstream
-CD4 protein readily binds to the attachment protein
-The protein capsid fuses with the cell surface membrane, allowing for the RNA and enzymes of HIV enter the helper T cell
-The HIV reverse transcriptase converts the virus’s RNA to DNA
-Newly made DNA is inserted into the cell’s nucleus and is inserted into its DNA
-HIV DNA creates mRNA which allows for new HIV particles to be created
-These then break away with a part of the cell surface membrane forming their lipid envelope

Question 3

How does HIV cause AIDS?

Answer 3

HIV causes AIDS by killing or interfering with the normal functioning of helper T cells.

Question 4

How is AIDS controlled and treated?

Answer 4

AIDS treatment involves antiretroviral therapy.

Question 5

How does the ELISA test work?

Answer 5

-Apply sample to surface to which the antigens will attach
-Wash the surface several times to remove any unattached antigens
-Add the antibody that is specific to the antigen that we are trying to detect
-Wash the surface to remove any unattached antibodies
-Add a second antibody with enzyme attached to the first antibody
-Add a colourless substrate of the enzyme, which will then be turned into a coloured product
-The amount of antigen present is relative to the intensity of the colour that develops

Question 6

Why are antibiotics ineffective against viral disease?

Answer 6

Viruses have no metabolic mechanisms for an antibiotic to disrupt, therefore rendering it useless against a virus.