HIV and Viruses

Question 1

HIV

Answer 1

Human Immunodeficiency Virus

leads to AIDS

Question 2

AIDS

Answer 2

acquired immune deficiency syndrome
immune system deteriorates and eventually fails
AIDS victim TF more vulnerable to other infections as T-Helper cell count is critically low
initially, minor infections succombed to.
more serious infections ensue as immune system cell no.s decrease

Question 3

HIV structure

Answer 3

spherical structure
RNA (genetic material) core
proteins i.e. reverse transcriptase
outer protein coating - capsid
extra outer layer - envelope - membrane stolen from previous host’s cell membrane
attachment proteins on outside to attach to T-Helper cell

Question 4

HIV replication

Answer 4

attachment protein attaches to receptor molecule on T-Helper cell
capsid released into cell and releases RNA into cytoplasm
reverse transcriptase makes complementary strand of cell’s DNA from viral RNA template
double stranded DNA is made and inserted in human DNA
Host cell enzymes used to make viral proteins and DNA within human DNA
viral proteins assembled into new viruses which bud from the cell and go on to infect other cells.
T-cells eventually killed

Question 5

Latency period

Answer 5

during initial infection period, HIV replicates rapidly and infected person may experience flu-like symptoms
replication then drops to lower level - LATENCY PERIOD
can last for years
infected person WON’T experience any symptoms

Question 6

Antibiotics

Answer 6

kill bacteria by interfering with metabolic reactions and targeting bacterial enzymes and ribosomes used in these reactions
ONLY target bacterial enz. and rib. so don’t damage human cells
Viruses use host’s cell enz. and rib. so antibiotics can’t inhibit human viruses as don’t target human processes

Question 7

Antiviral drugs

Answer 7

target virus-specific enzymes
i.e. HIV reverse transcriptase => reverse-transcriptase inhibitors
humans don’t use these enzymes so drugs designed to inhibit them without affecting host cell

Question 8

NO CURE

Answer 8

no cure or vaccine but antiviral drugs can slow the progression
reducing its spread via unprotected sexual intercourse, infected bodily fluids, and HIV + mother to foetus (antiviral drugs during pregnancy reduce this chance)