2C-cells and immune system Flashcards
what are antigens
molecules that can generate an immune response when detected by the body
why are drugs given to a person who just had an organ transplant
because the cells will have some antigens that are different to the persons’ so the foreign antigens trigger an immune response leading to the rejection of the organ so drugs are taken to supress the recipients immune response
what is a phagocyte
a white blood cell
what is phagocytosis
engulfment of pathogens
what are the steps in phagocytosis
the phagocyte recognises the foreign antigens on a pathogen making the cytoplasm of the phagocyte move around the pathogen engulfing it, the pathogen is now contained in a phagocytic vacuole. then the lysosome fuses with the phagocytic vacuole and the lysozyme breaks down the pathogen.
The phagocyte presents the pathogen’s antigens by sticking the antigens on its surface to activate other immune system cells. its acting as an antigen presenting cell.
what is a T-cell
another type of white blood cell it has receptor proteins on its surface to bind to complementary antigens presented to it by phagocyte
what is a helper T-cell
release chemicals that activates and stimulates phagocytes and cytotoxic T-cells which kill abnormal and foreign cells. they also active B-cells
what are B-cells
a white blood cell covered with antibodies forming an antigen-antibody complex. B-cells have a different shaped antibody on its membrane so different one bind to different antigens
what is clonal selection and how do B-cells divide into plasma cells
when an antibody on the surface of a B-cell meets a complementary shaped antigen this is called clonal selection. this together with the substances released for T-cells activates B-cells. the activated B-cell divides into plasma cells
what are monoclonal antibodies
plasma cells and B-cells are identical so secrete antibodies specific to the anitgen
what is agglutination
antibody has two binding sites so binds to two pathogens at the same time so they become clumped together
What does the specificity of an antibody depend on
the variable regions which for the antigen binding sites
what do all antibodies have in common
they have the same constant regions
what is the antigen-antibody complex structure
refer to pg 118
what are the two immune responses
cellular and humoral response
what is the cellular response
the T-cells and the other immune system cells that they interact with
what is the humoral response
B-cells, clonal selection and production of the monoclonal antibodies
what is the primary response
when an antigen enters the body for the first time and activates the immune system.
why is primary response slow
because there aren’t many B-cells making the the antibodies needed to bind to it. meanwhile infected person shows symptoms.
How are memory cells produced
after being exposed to the antigen, T-cells and B-cells produce memory cells. Memory T-cells remember the antigen second time round and memory B-cell record the specific antibodies needed to bind to the antigen.
what is the secondary response
if smae pathogen enters the body the immune system produces a quicker, faster response
