Immunology test

Term

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5 marker first question: phagocytosis stages

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Definition

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1. Phagocyte recognises foreign antigens on a pathogen
2. cytoplasm of the phagocyte moves around the pathogen, engulfing it
3. pathogen now contained in a phagocytic vacuole in the cytoplasm of the phagocyte
4. lysosome fuses with the phagocytic vacuole and releases lysozymes that break down the pathogen
5. phagocyte presents the pathogens antigens: it sticks the antigens on its surface to activate other immune system cells

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Terms in this set (11)

5 marker first question: phagocytosis stages

4 marker: how are B cells activated

- T cells activate B cells
- white blood cells covered in antibodies that secrete antibodies
- each B cell has a different shaped antibody on its membrane
- when the antibody on the surface of a B cell meets a complementary shapes antigen, it binds to it
- activated by clonal selection
- activated B cells divide into plasma cells

4 marker: how are T cells activated

- phagocytes activate T cells
- receptor proteins on T cell's surface bind to complementary antigens presented by phagocytes
- helper T cells: release chemical signal that activate and stimulate phagocytes and cytotoxic T cells
- cytotoxic T cells: kill abnormal and foreign cells

Shows stages of ELISA test: why is the antibody washed out after each stage

Removes any unbound secondary antibodies. No primary antibodies means all secondary antibodies are washed away.

Diagram of time in one axis and quantity of antibodies in the blood of one person on the other: the person has a vaccination and a booster a few days later. Explain the difference in quantity of antibodies in the blood

First stage of primary response

First stage: primary response
- not many B cells that can make the antibody needed to bind to it. The body produces enough of the tight antibody to overcome infection while the infected person shows symptoms of a disease.
- T&B cells produce memory cells that remain in the body and remember the specific antigen for the second time exposed.
- Memory B cells record specific antibodies needed to bind to the antigen.

Second stage: secondary response
-if the same pathogen enters the body again, the immune system will produce a quicker, stronger immune response
- clonal selection speeds up and memory B cells are activated and divide into plasma cells that produce the right antibody for the antigen
- memory T cells are activated and divide into the correct type of T cells to kill the cell carrying the antigen

4 marks: 2 antigens (1 measles 2 another infection) Why will the antibody for measles only work for measles and why the antibody for measles won't work for the other antigen

Specific to only measles: binding site

- variable regions that decide the specificity of an antibody that form the antigen binding sites
- variable regions have unique tertiary structures due to the order of amino acids thats complementary to one specific antigen

2 marks: what a measles antigen is

protein molecules on the surface of the measles pathogen that generate an immune response when detected by the body. They help the body identify the measles pathogen which generates an immune response and causes phagocytosis to occur

Last question: graph with time on x axis and y axis was number of people with HIV and AIDS:
HIV increased over time
AIDS decreased over time

2 marks: explain why number of people with HIV has increased

- no cure
- antiviral drugs taken to slow the progression of HIV infection and AIDS in an infection person

Last question: graph with time on x axis and y axis was number of people with HIV and AIDS:
HIV increased over time
AIDS decreased over time

2 marks: why the number of people with AIDS has decreased

People are more aware the disease and use condoms, limiting sexual partners, and use clean needles.