Immunity Flashcards
What is the disadvantage of taking a vaccine orally?
It could be broken down by enzymes in the gut or the molecules of the vaccine may be too large to be absorbed into the blood
What are some ethical issues surrounding the use of vaccines?
.people may put themselves at risk because they think they are immune after taking a vaccine (eg someone may have unprotected sex after having a new HIV vaccine)
.it’s tested on animals, and some people are against this
.some people might not want to take it due to side effects, and others may think this is unfair that they dont take it since they are protected by herd immunity
What is the difference between the cellular and humoral response?
Cellular: T-cells and other immune system cells involved (e.g phagocytes)
Humoral: B-cells, clonal selection and monoclonal antibody production
Active vs passive immunity
Active:
Natural- your own body makes antibodies after you catch a disease
Artificial- You get a vaccination with antigens, and your body produces antibodies for it
Passive:
Natural- Babies get antibodies from the placenta and in breast milk of their mum during pregnancy
Artificial- you get injected antibodies from another person for a disease
Primary response vs secondary response
Primary-
antigen enters the body for the first time. The response is slower because the body doesn’t have enough b-cells that can make antibodies to bind to it. The person will show symptoms of the disease throughout.
After being exposed to the antigen, T-cells and B-cells produce memory cells that will recognise the antigen a second time.
Secondary-
If the same pathogen enters the body again there is a quicker and stronger response because the body has memory cells that will divide into plasma cells to produce the right antibodies much faster. The pathogen is ridden of before you start to start to show symptoms
Describe how HIV is replicated
.Attachment protein binds to receptors on the T cells
.The capsid is released into the cell
.Reverse transcriptase converts RNA to DNA
.Then this is used to produce viral proteins that make up the HIV
.The proteins are then assembled, which forms new HIV, and are then released.
Describe how HIV is replicated once inside helper T cells
.RNA is converted to DNA using reverse transcriptase
.DNA is inserted into helper T cell DNA
.DNA is transcribed into HIV mRNA
.HIV mRNA is translated to form new viral proteins
Explain how HIV affects the production of antibodies when AIDS develops in a person
T cells are killed,so they can’t stimulate release of B cells to divide, so less monoclonal antibodies are produced
Describe the structure of HIV
.Capsid containing the RNA
.Reverse transcriptase
.Attachment protein attached to membrane made of nuclear envelope
A mother who was infected with HIV gave birth to a baby. The baby tested positive using
this test. This does not prove the baby is infected with HIV.
Explain why.
.Children receive HIV antibodies from their mothers (maternal antibodies)
.So the solution will always turn blue
