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Flashcards in HIV Deck (18):

How do prokaryotic cells divide?

By binary fission, they divide exponentially.


What does HIV stand for?

Human Immunodeficiency Virus (retrovirus)


What makes us a HIV cell?

An RNA strand, a GP120 glycoprotein, a capsid, a matrix, a lipid envelope, a CD4 surface protein and reverse transcriptase.


What's the function of the RNA strand?

A template for DNA formation.


What's the function of the capsid?

Protects the RNA.


What's the function of the lipid envelop?

It fuses with the host cell membrane to gain entry to the host cell.


What's the function of the GP120?

Identifies the host cell and enables the virus to attach to the host cell.


What's the function of reverse transcriptase?

Makes DNA from the RNA template.


Where are the HIV cells contained?

They are contained within the host cell and can't be destroyed without destroying or damaging the host cells.


How does viral replication occur?

HIV invades the body and circulates in the blood. They invade T-helper cells due to the presence of the CD4 surface protein. The virus membrane fuses with the hosts CSM. The viral RNA and enzymes enter the cell and reverse transcriptase produces DNA from its RNA. The DNS is integrated into the hosts DNA by another HIV enzyme, integrase. The viral DNS is transcribed to viral mRNA, this leaves the nuclear pore and is translated to produce and assemble new viral proteins. The new virus particles bud out of the T-cell taking some of the CSM with them as there envelope and kills the cell as they leave. T-helper cells and macrophages are infected and the process repeats. Viruses are unable to exist and reproduce freely in the environment. They need a host cell.


What is HIV/AID's?

HIV DNA only infect humans, HIV attacks your T-cells and uses them to make copies of itself. When HIV destroys many cells it develops to AID's. People who have fewer T-helper cells are more susceptible to infection, when this becomes apparent i.e. many infections it becomes AID's this can take 10 years.


What are the initial symptoms of HIV?

Minor infections e.g. flu


What are the progressive symptoms of HIV?

Serious bacterial infections e.g. tuberculosis


What are the late stage symptoms of HIV?

Very serious infections e.g. taxoplasmosis.


What are the treatments for HIV?

Antibiotics work by keeping the bacteria from being able to reproduce by killing the bacteria mostly by destroying it enzymes. Hence they only kill bacterial enzymes. However, viruses are like parasites of our own cells, to get rid of them you would have to destroy the cell itself and regular enzymes. Antiviral drugs target few viral specific enzymes, in HIV reverse transcriptase. As the hose cell doesn't use the enzyme so the virus can be destroyed without damaging the hose cell. There is no cure for HIV at present, the antiviral drugs slow down the progression of from HIV to AID's. Methods to reduce the spread of HIV include practicing safe sex and not sharing needles.


How is HIV diagnosed?

Indirect ELISA


What is the ELIZA procedure based on?

The test works on the basis that an infected person will have the antibodies so if these are detected the person is infected m


How is the ELZIA procedure carried out?

- add the antibody to a Petri dish
- add the patients blood to this
- remove the blood and anything else unbound
- add animal substrate which attaches to the HIV
- remove everything unbound again
- add the colour changing enzyme
- if the colour changes then the patient has HIV