Antibody (immunoglobin protein)

Antibody (immunoglobin protein)  Secreted by B-lymphocytes and produced in response to a specific (foreign) non-self antigen  B-lymphocyte's receptor site matches the non-self-antigen  Each antibody is produced by one type of B-lymphocyte for only one type of antigen  An antibody is Y-shaped o The two ends of the Y are called the Fab fragments o The other end is called the Fc fragment o Fab fragment is responsible for the antigen-binding properties o Fc fragment is the effector component and triggers the immune response  B cells divide and form memory cells and antibody-secreting plasma cells: o Agglutination makes pathogens clump together o Antitoxins neutralise toxins produced by bacteria o Lysis digests bacterial membrane, killing the bacterium o Opsonisation coats pathogen in protein that identifies them as foreign cells Types of Immune Response  Lymphocytes undergo maturating before birth, producing different types of lymphocytes  Humoral response - B lymphocytes o Produce and release antibodies into blood plasma o Produce antibodies from B plasma cells o Recognize foreign antigen directly  Cellular response - T lymphocytes o Bind to antigen carrying cells and destroy them and/or activate the humoral response o Recognize foreign antigens displayed on the surface of normal body cells  Primary respon