hummoral immunity Flashcards
what is clonal selection
when an antigen enter the blood or tissue fluid there will be a b cell which has the complementary antibody on its cell surface membrane which attaches to the antigen as they are complementery the antigen enter the b cell and produces the antigen on the b cell surface this cause helper t cells to bin to these b cells stimuating the b cels to divide via mitosis to produce more antidodies specific to foreign antigen- plasma cells or memory cells
what can b cells form into
plasma cells which secrete antibodies into he blood plasma which can amke up to 2000 antibodies every second and are responsible for the immediate defense of the body against infection
memory cells are responsible for secondary immune response memory cells do not produce antibodies but circulate blood for decades when they encounter antigen at a later date they divide rapidly and form plasma cell and more memory cellsthe plasma cell destroy the payhogen and the increase in memory cells prepare the immune system if a pathogen was to infect in the future
what are antibodies
protiens with twob binding sites synthesized by b cells are complementary to a specific antigen which they destroy
how are antibodies made
they are made from 4 polypeptide chains two are long and heavy and are called heavy chains and the other two are light chains each antibody has a specific binding site which fits precisely onto a specific anigen forming an antigen antibody complex as the binding site is different it is called the variable reigion and the rest of the antibody is called the constant reigion
how do the antibodies work
they cause agglunitation of the bacterial cells in this way clumps of bacterial cells are formed amking it easier for phagocytes to destroy
they then serve as marker that stimulate phagocytosis to engulf bacterial cells
what are monoclonal antibodies
single antibody isolated and cloned
how are monoclonal antibodies used to treat cancer cells
tehy are produced and are specific to the antigens on the cancer cell these antibodies are given to the patient and attach to the receptors on the cancer cell this blocks the chemical signals which stimulate uncontrolled growth (herceptin)
what are the advantages of monoclonal antibodies
it doesnt cause side effects as it is direct and only targets specific cells
what are magic bullets
onoclonal antibodies that have a radioactive or cytotoxic drug attatched so when they are given to the patient they ay=ttach to the cancel cell but are destroyed instead this can be given in smaller doses to reduce side effects
how can monoclonal antibodies be used to diagnose prostate cancer
they often produce a protien called psa leading to abnormally high levels in the blood by using monoclonal antibodues that interact with the antigen it is possible to obtain a measure of the psa in the blood
hhow is monoclonal antibodies used in pregnancy testing
placenta produces the protien hcg and its found in urine the monoclonal antibody present on strip and are linked to colored particles binds to the antibody and causes a an antibody antigen color complex to form which move along until it is trapped by a different antibody crearing a colored line
what are the ethical use of monoclonal antibodies
production of monoclonal antibodies include inducing cancerous growth in mice
it has been used to treat a number of disease so the benefits may outweigh the harms caused to rats
