HIV

Question 1

what does HIV stand for

Answer 1

Human Immunodeficiency Virus

Question 2

explain how HIV replicates

Answer 2

-HIV enters the blood
- attachment proteins on HIV bind to the CD4 proteins (receptors) on Th cell
- HIV protein capsid fuses with cell surface membrane of Th cell
- RNA and reverse transcriptase enzyme enters the cell
- HIV DNA moves into Th cell nucleus where it is joined to Th cells DNA
- DNA is used to make HIV mRNA copies

translation of viral mRNA in ribosomes
- this leads to the assembly of new HIV particles
- HIV particles breakaway from Th cells with some of it’s cell surface membrane ( this process is called budding)
- the cell surface membrane makes up the lipid envelope

Question 3

What is the function of HIV mRNA

Answer 3

Includes instructions to make viral proteins (capsid, reverse transcriptase, attachment proteins)

Question 4

What is the function of the RNA molecule in this virus

Answer 4

Carries genetic information

Question 5

Explain how the destruction of T- cells by HIV lead to the death of an infected person

Answer 5

• not enough T cells to activate B cells
• person is more prone to disease

Question 6

Explain why a vaccine for HIV may not be effective considering HIV enters host cells

Answer 6

HIV enters cells before antibodies can bind to it

specific antibody no longer binds