| HIV meaning | - Human immunodeficiency virus |
| Structure of HIV | - RNA + some proteins (e.g reverse transcriptase)
- Proteins coat, capsid
- Lipid envelope
- Attachment proteins
- Retroviruses |
| HIV replication inside host cells | - Attachment proteins binds to complementary receptor on host helper T cells
- Genetic material inserted into cell
- Host cell enzymes used to make viral proteins from viral DNA
- Viral proteins assembled into new viruses, leaves cell to infect others |
| Reverse transcriptase in binary fission of HIV | - Makes complementary strand of DNA from viral RNA template
- Makes double-stranded DNA
- Inserted into human DNA |
| How HIV causes AIDS | - Kills or interferes helper T cells
- Immune system cannot stimulate B cells or cytotoxic T cells
- More susceptible to infections + cancers |
| How antibiotics work | - Kills bacteria by interfering with their metabolic processes
- Only targets bacterial enzymes + ribosomes
- Don't damage human cells |
| Why antibiotics are ineffective against viruses | - Viruses use host cell's enzymes + ribosomes
- Antibiotics cant inhibit them because they don't target human cells |
| Reverse transcriptase inhibitors | - Most antiviral drugs target virus-specific enzymes
- HIV uses reverse transcriptase to replicate
- Human cells don't use it, so drug can inhibit virus without affecting host cell |
| The ELISA test | - Enzyme-linked immunosorbent assay
- Used to see if someone has antibodies to a certain antigen
- Can test for pathogenic infections, allergies |
| How ELISA test works | - Has an antibody which has an enzyme attached to it
- This enzyme can react with a substrate to produce coloured product
- If there's a colour change, shows antigen or pathogen is present |
| Different types of ELISA tests | - Direct ELISA, uses 1 antibody
- Indirect ELISA, uses 2 different antibodies |
| Treatment and control of HIV + AIDS | - HIV does not kill individuals directly
- No cure or vaccine
- Antiviral drugs can slow progression of HIV
- Controlled by avoiding unprotected sex, and exchanging bodily fluids |
