2C-HIV and viruses Flashcards
what does HIV stand for
human immunodeficiency virus
what does AIDS stand for
acquired immune deficiency syndrome
what is AIDS
where a person’s immune system deteriorates and finally fails making someone with AIDS vulnerable to other infections
how does HIV infect cells
HIV infects and kill helper T-cells that act as host cell for the virus.
what is the role of helper T-cells and why are they important
they send chemical signals that activate and stimulate phagocytes , cytotoxic T-cells and B-cells
why can’t they immune system responsd to infections effectively
because theyre arent enough helper T-cells
what is the initial infection period of HIV
during initial infection period the HIV replicates rapidly and person has flu like symptoms
what is the latency period
after the initial infection period HIV replication drops to a lower level . during this period they wont experince symptoms
what are the symptoms of AIDS
minor infections of mucous membranes and recurring respiratory infections
what happens to the immune system with AIDS
number of immune system cells decrease and patient become susceptible to serious infections e.g diarrhoea, tuberculosis
what happens at the last stages of AIDS
patient has very low number of immune system cells and can develop serious infections like toxoplasmosis of the brain and candidiasis of the respiratory and these are what kill the patient not HIV itself
the structure of HIV
pg 131`
how and where does the HIV replicate
reproduces inside the cell of organism it has infected. replicates inside the helper T-cell of the host coz doesn’t have thr equipment to reproduce on its own so uses host cell
steps of the HIV replication
attachment protein attaches to receptor molecule on cell membrane of helper T cell
capsid released into cell and releases GM (RNA) into cytoplasm
in cell revers transcriptase makes complementary strand of DNA from RNA template
so double stranded DNA is made and inserted into human DNA
host cell enzymes make viral proteins from the viral DNA found in the human DNA
viral proteins assembled into new virus which bud from the cell and go to infect other cells
how do antibiotic kill bacteria
by interfering with their metabolic reactions
