HIV

Question 1

What does HIV stand for

Answer 1

human immunodeficiency virus

Question 2

What does the HIV cause

Answer 2

AIDS (acquired immune deficiency syndrome)

Question 3

Draw the structure of HIV

Answer 3

See pg 119 textbook

Question 4

What organelle does HIV have (6 points)

Answer 4

1) lipid envelope
2) attachment proteins
3) matrix
4) capsid
5) genetic material (RNA)
6) reverse transcriptase (enzyme)

Question 5

What group of viruses does HIV belong to

Answer 5

retroviruses

Question 6

How does HIV replicate

Answer 6

uses its genetic material to instruct the host cell’s biochemical mechanisms to produce the components required to make new HIV

Question 7

What are the steps of HIV replication (8 points)

Answer 7

1) HIV enters the bloodstream and circulates around the body
2) protein on HIV binds to protein CD4 T-helper cell
3) protein capsid fuses with cell-surface membrane and the RNA & enzymes of HIV enter T-helper cell
4) HIV reverse transcriptase converts the virus’s RNA into DNA
5) this DNA is moved into T-helper cells nucleus where it is inserted into the cells DNA
6) the HIV DNA in the nucleus creates mRNA using the cells enzymes, which contains instructions for making new viral proteins and the RNA to go into the new HIV
7) mRNA passes out of nucleus through nuclear pore and uses the cells protein synthesis mechanisms to make HIV particles
8) HIV particles break away from T-helper cells with a piece of the cell-surface membrane, that forms their lipid envelope

Question 8

What does a person become when infected with HIV

Answer 8

HIV positive

Question 9

Does a HIV positive person automatically have AIDS and why

Answer 9

no, because it often lies dormant so AIDS is only formed when it recommences many years later

Question 10

What does HIV attack

Answer 10

T-helper cells

Question 11

What does HIV mean for the number ofT-helper cells

Answer 11

it decreases them from 800-1200 in each mm3 to 200mm3