TOPIC 2 HIV and aids

Question 1

What does HIV affect?

Answer 1

-The immune system

Question 2

What does HIV lead to?

Answer 2

-AIDS

Question 3

What are the consequences of aids?

Answer 3

-Immune system deteriorates and eventually fails

Question 4

What are the host cells for HIV?

Answer 4

Helper T cells

Question 5

What does HIV do to the T cells?

Answer 5

-Infects and eventually kills them

Question 6

Why do people infected with HIV develop AIDS?

Answer 6

-Helper T cells are at a critically low level

Question 7

Why are people with HIV immunocompromised?

Answer 7

-Without enough helper T cells the immune system cannot mount an effective response to infections as other immune system cells don’t behave as they should

Question 8

What happens during the initial infection period?

Answer 8

-HIV replicates rapidly
-The infected person may experience severe flu-like symptoms (as the immune system mounts a response)

Question 9

What is the latency period?

Answer 9

-When HIV replication drops to a lower level
-The person doesn’t experience any symptoms

Question 10

How long do AIDs take to develop typically develop?

Answer 10

usually around 10 years

Question 11

What are the initial symptoms of aids?

Answer 11

-Minor infections of mucous membranes (the inside of the nose, ears and genitals)
-Recurring respiratory infections

Question 12

What happens as aid progresses?

Answer 12

-The number of immune system cells decreases
-More susceptible to serious infections such as chronic diarrhoea, severe bacterial infections and TB

Question 13

What factors affect how long AIDS sufferers survive?

Answer 13

-Existing infections
-Strain of HIV they are infected with
-Age
-Access to healthcare

Question 14

What is the structure of HIV?

Answer 14

-Spherical
-Core contains genetic material (RNA transcriptase)
-Proteins- including the enzyme reverse transcriptase used for virus replication
-Capsid and envelope (made from stolen membrane of the host cell)
-Attachemnt protein- allows HIV to attach to host helper T cell

Question 15

Why do viruses (specifically HIV)) replicate inside host cells?

Answer 15

-They do not have the enzymes and ribosomes to replicate on their own

Question 16

What is step 1 of HIV replication?

Answer 16

The attachment protein attaches to a receptor molecules on the T cell membrane

Question 17

What is step 2 of HIV replication?

Answer 17

The capsid is released into the cell, it uncoates and realease the genetic material (RNA) into the cytoplasm\\

Question 18

What is step 3 of HIV replication?

Answer 18

Reverse transcriptase is used to make a complementary strand of DNA from a viral RNA template

Question 19

What is step 4 of HIV replication?

Answer 19

From this double-stranded DNA is made and inserted into the human DNA

Question 20

What is step 5 of HIV replication?

Answer 20

Host cell enzymes are used to make viral proteins from the viral DNA found within the human DNA

Question 21

What is step 6 of HIV replication?

Answer 21

Viral proteins are assembled into new viruses, which bud from the cell and go and infect other cells

Question 22

How do antibiotics kill bacteria?

Answer 22

-By interfering with their metabolic reactions (target bacterial enzymes and ribosomes)

Question 23

Why do antibiotics only target bacterial enzymes?

Answer 23

So they don’t damage human ones

Question 24

Do antibiotics kill viruses?

Answer 24

No

Question 25

What are antiviral drugs used for?

Answer 25

To target the very few virus-specific enzymes

Question 26

What are the best ways of reducing HIV infection rates?

Answer 26

-Reducing the spread- protected sex, not sharing bodily fluids and not passing HIV onto children

Question 27

What are used to slow down the progression of HIV?

Answer 27

-Antiviral drugs

Question 28

What reduces the chance of the baby being HIV positive?

Answer 28

-The mother taking HIV drugs during pregnancy