immunity Flashcards
phagocytosis
-receptors detect the pathogen
-the phagocyte engulfs the the pathogen into vacuole
-vacuole binds with a lysosome to make a phagolysosome
-the lysosome releases litic enzymes that digest/ hydrolyse the pathogen
-the pathogen remains are released via exocytosis
-some of the antigen will be displayed on the cell to alert other cells of foreign antibodies (antigen presenting cell)
cell mediated immunity
-antigen is presented by antigen presenting cell
-helper T-cell with complimentary receptor binds to the antigen
-helper T-cell is activated and goes through mitosis
-this forms cytotoxic T cells and more helper T cells
-cytotoxic T cells produce perforins to kill cells by making holes in the cell membrane, water enters causing the cell to burst
-only works on whole cells
HIV replication
-HIV attachment proteins complimentary to receptors on helper T cells
-virus nucleic acid enters the cell
-reverse transcriptase converts RNA to DNA and is inserted into the host cells genome
-DNA is transcribed and the HIV capsid and enzymes are made by the host cells ribosomes
-everything is assembled by the host cells rough ER and golgi into new virus protein, capsid and enzyme
-virus are assembled and released
humoral immunity
-T helper cells bind to complimentary antigens on specific B cells (clonal selection)
-T helper cells activate specific B cells
-B cells rapidly divide by mitosis to produce plasma and memory B cells (clonal expansion)
-these cloned plasma cells produce specific complimentary antibodies to the antigens on the pathogens
-antibodies destroy the pathogen
vaccines
-vaccines contain antigens/ weak patogens
-memory B cells are made
-on second exposure B memory cells are made
-memory cells and plasma cells rapidly produce antibodies
-antibodies destroy pathogens
ELIZA test
-first antibody binds/ complimentary to antigen of interest
-second antibody with enzyme is added
-enzyme binds to substrate
-unbound antibody is washed away
-solution added and colour change seen
