Chapter 5 H

Question 1

how does HIV replicate (step 1)

Answer 1

1.Binding-the HIV cell in the bloodstream circulates until it finds a cell with a CD4 protein on it (usually a white blood cell). When HIV attacks a cd4 cell the virus binds to molecules on the surface of the CD4 cell.

Question 2

how does HIV replicate (step 2)

Answer 2

2. fusion-after HIV attaches itself to a host CD4 cell, the HIV viral envelope fuses with the CD4 cell membrane. fusion allows HIV the CD4 cell. Once inside the CD4 cell, the virus releases HIV RNA and HIV enzymes, such as reverse transcriptase and integrase.

Question 3

how does HIV replicate (step 3)

Answer 3

3. reverse transcription- HIV uses reverse transcriptase to convert its genetic material-HIV RNA- into HIV DNA.

the conversion of HIV RNA to HIV DNA allows HIV to enter the CD4 cell nucleus and combine with the cells genetic materials-cell DNA

Question 4

how does HIV replicate(step 4)

Answer 4

4.integration-once inside the host CD4 cell nucleus, HIV releases integrase, a HIV enzyme.

HIV uses integrase to insert (integrate) its viral DNA of the host cell.

Question 5

how does HIV replicate(step 5)

Answer 5

5.replication-once HIV is integrated into the host CD4 cell DNA, the virus begins to use the machinery of the CD4 cell to create long chains of HIV proteins.

the viral DNA is transcribed and translated by the host cell to produce new viral proteins, which are the building blocks for more HIV.

Question 6

how does HIV replicate(step 6)

Answer 6

6.assembly- during assembly, new HIV RNA and HIV proteins are made by the host CD4 cell.

these move to the surface of the cell and assemble into non-infectious HIV.

Question 7

how does HIV replicate(step 7)

Answer 7

7.budding- budding, immature (non-infectious) HIV pushes itself out of the host CD4 cell taking some of the host cell membrane to form the viral envelope. this kills the T helper cells.

non-infectious HIV cant infect another CD4 cell.

once outside the CD4 cell, the new HIV releases proteases, a HIV enzyme.

Question 8

how are monoclonal antibodies made

Answer 8

1. a mouse is injected is exposed to an antigens
2. the mouse’s b cells produce a mixture of antibodies (polyclonal). these are extracted from the spleen.
   3.these are mixed with cells that can divide outside the body( cancer cells)
   4.both types of cells fuse
3. fused cells clone themselves
4. the right clone is selected and grown on a large scale
   7.the antibody is extracted from the growth medium

Question 9

Name the 7 steps of HIV replication

Answer 9

1.binding
2.fusion
3.reverse transcription
4.integration
5. Replication
6.assembly
7.budding