hiv and viruses Flashcards
What is aids
Conditions where the immune system deteriorates and eventually dies
- makes patients more vulnerable to other infections
What happens to T helper cells when u have HIV
HIV infects and eventually kills T cells which are important in immune response
- no effective response against infection
at what point does HIV develop into AIDS
When T helper cells track a critically low level
Draw HIV molecule
page 54 textbook
Describe the core of a HIV molecule
Contains genetic material, RNA and some proteins including enzyme reverse transcripts which is needed for virus replication
What is the outer coating of the protein HIV called?
The capsid
What is the extra outer layer of HIV called and what is it made from?
Extra out of layer called an envelope made of membrane stolen from cell membrane of the previous host cell
Where are the attachment proteins and what do they do to help HIV?
Sticking out of the envelope are loads of copies of an attachment protein that help HIV attached to the host helper T cell
Describe how HIV replicates
- The attachment protein attaches to a receptor molecule on the cell membrane of a host helper T cell
- The cap is released into the cell where it undercoats and releases the genetic material (RNA) into the cell cytoplasm
- Inside the cell reverse transcript is used to make a complimentary strand of DNA from the viral RNA template
- From this double stranded DNA is made and inserted into the human DNA
- Host cell enzymes are used to make viral proteins from the viral DNA found within the human DNA
- The viral proteins are assembled into new viruses which bad from the cell and go on to infect other cells
What are the initial symptoms of AIDS?
Minor infections of mucus membranes such as inside the nose and ears and recurring respiratory infections
Antibiotics don’t work against viruses. explain why
- antibiotics kill bacteria by interfering with their metabolic reactions they target the bacterial enzymes and ribosomes used in these reactions
- Bacterial enzymes and ribosomes that are different from human enzymes and ribosomes antibiotics are designed only to target the bacterial ones so they don’t damage human cells
- Viruses don’t have their own enzymes and ribosomes they use the ones in the house cell so because human viruses use human enzymes and ribosomes to replicate antibiotics can inhibit them because they don’t target human processes
- Most antibiotic drugs are designed to tell a few virus specific enzymes but HIV uses reverse transcripts to replicate and human cells. Don’t use this enzyme.
- This means that antibiotics can’t be used for this virus without affecting the host cell
There’s no cure for HIV, but what can be used to prevent it?
Anti-viral drugs, slowdown progression of HIV
Best way to control is reducing the spread
