HIV/ AIDS Flashcards
Why are viruses (in general) difficult to destroy?
- Because viruses replicate inside of host cells, making it difficult to destroy the virus without harming the host cells.
Why are antibiotics ineffective against viruses?
- Because viruses have no cell wall -like bacteria do- so cannot be destroyed by antibiotics (antibiotics work by causing damage to the cell wall.)
() - extra info for clarification.
What is HIV’s structure?
- Has RNA and enzyme, reverse transcriptase within a capsid.
- Has a lipid envelope
- Has attachment proteins attached to the lipid envelope.
Diagram in Yousaf notes
What is the “capsid” in HIV and what does it do?
- Capsid: protein coat around genetic material/ reverse transcriptase.
- FUNCTION: protects viral genetic material.
What do the attachment proteins in HIV do?
- Allows the HIV to attach to receptors on the surface of Th cells.
What is the function of “reverse transcriptase” in HIV?
- Reverse transcriptase is an enzyme which converts HIV RNA into DNA.
What is the lipid envelope in HIV, where does it come from?
- Extra outer layer of virus, made out of membrane taken from host cell’s membrane.
What are the stages of HIV replication in Helper T cells?
MS response!! If you want to look at MS for these responses: refer to “Immune System PMT dox”
1.) HIV attaches to receptors on surface of helper T cells.
2.) Phospholipid envelope fuses with plasma membrane of cell, RNA/ reverse transcriptase enters the helper T cell.
3.) Cytoplasm of cell: reverse transcriptase converts viral RNA into DNA.
4.) DNA incorporated into helper T cell’s DNA.
5.) DNA transcribed into HIV mRNA.
6.) HIV mRNA translated into new viral proteins; new viral proteins are produced for assembly into viral particles.
7.) Viral particles are assembled (put together - containing the proteins produced) and released from the cell.
() - extra info for clarification.
Diagram in Yousaf notes.
How does HIV cause the symptons of AIDS?
- HIV virus replicates in helper T cells, so many helper T cells are* destroyed* that this affects normal functioning of immune system
- Helper T cells* destroyed* by virus, host unable to produce adequate immune response to other pathogens. Could lead to severe infections/ cancer.
- The destruction of the immune system leads to death.
MS Key Word = DESTROYED NOT DAMAGED!!
True or False
The HIV virus will directly cause someone to die.
- False.
- It is the destruction of the immune system that leads to death, rather than HIV directly.
True or False
A patient who has HIV and a patient who has AIDS are the same.
- FALSE!
- Said to have HIV when virus has infected you, said to have AIDS when so many helper T cells have been destroyed by HIV replication that it interferes with normal functioning of immune system.
What does HIV stand for?
- Human immunodeficiency virus
