AIDS and HIV replication Flashcards
AIDS: causative agent
HIV
Human Immunodeficiency Virus
AIDS mode of transmission
- Sexual
- Infected needles/syringes
- Blood transfusion
- Transplacental
AIDS symptoms
Vague and ill-defined
- Oral thrush
- Kaposi sarcoma (a type of skin cancer)
- Fatigue, fever
- Weight loss, diarrhoea
- Enlargement of lymph glands
- Pneumonia
AIDS prevention
- Dont share tattoo needles
- ELISA done for all pregnant women
- Use disposable syringe always
- Safe and protected sexual practices
What type of virus is HIV?
RNA virus
Retrovirus
Why is HIV called a retrovirus?
contains reverse transcriptase enzyme
- It is called a retrovirus because of its ability to transcribe RNA into DNA once it enters the host cell by the process of reverse transcription
- Uses the reverse transcriptase enzyme for this process
Test to detect HIV
ELISA test
Enzyme Linked Immuno Sorbent Assay Test
What cells does HIV target and how is it transmitted
HIV targets cells of the immuno system
Transmits only through vital body fluids
Drug used to delay development of HIV
AZT (Azidothymidine) which prevents reverse transcription
Name the steps of HIV replication
HEADINGS ONLY
- Attachment
- Entry
- Viral DNA formation
- Integration
- Protein synthesis
- Assembly
- Budding and release
African Elephants, Victims of Intestinal Pain- Asses Burning
Attachment of HIV
FIRST STEP
The glycoprotein of HIV (gp-120 or GP₁₂₀) attaches to the CD₄ (clusters of differentiation 4) receptor of the host cell (T-helper cell)
Entry of HIV, Viral DNA formation and Integration
SECOND STEP
Entry of HIV,
The HIV releases its genetic material (RNA), reverse transcriptase enzyme and integrase enzyme into the cytoplasm of the T-helper cell
THIRD STEP
Viral DNA formation
Using the reverse transcriptase enzyme, the virus converts its RNA to DNA (reverse transciprtion)
STEP 4
integration
With the help of the integrase enzyme the newly formed viral DNA enters the nucleus of the T-helper cell and integrates itself with the host DNA
Protein synthesis
Step 5
using the host machinery, the host DNA Carrying the viral DNA carries out normal cell processes like replication of DNA, transcription (DNA to RNA) and translation (RNA to protein)
viral proteins are produced using host machinery
Assembly
Budding and Release
STEP 6
Assembly- New viral RNA and proteins move to the cell surface and assemble themselves to form new HIV virus
STEP 7
Budding and release: THe new virus buds out at the cell surface and leaves the cell to infect other T-Helper cells
What does HIV do =(
- T-cells unable to initiate cellular immune system :(
- T-helper cells unable to stimulate humoral immune system :(
