12.6 The Specific Immune System Flashcards
Antigens
Molecules on all cell surfaces. Allows the body to recognise the cell as self or non-self
Antibodies
Polypeptide involved in immune response
Immunoglobulins
Glycoprotein that binds to specific antigens on pathogen that triggered immune response.
Heavy chain
Section of the antibody that allows fir antigen-specific binding. Held together by disulfide bridges
Light chain
Allows expression and secretion of functional antibodies. Increases variability of antibodies
Antigen-antibody complex
When an antibody binds to an antigen
Agglutinin
Specialised antibody that binds foreign cells together, forming a clump (like glue)
T helper cell
Have receptors on cell-surface membrane, binding to surface antigens on APCs. Produce interleukins. These stimulate activity of B cells. Increases antibody production. Attracts macrophages
Interleukin
Type of cytokines that are secreted in order to bind to the pathogen via a receptor molecule on the cell’s surface
T killer cell
Destroys the pathogen carrying the antigen. Produces a chemical called perforin which kills the pathogen by creating perforations making it permeable
T memory cells
Long lifespan, part of immunological memory. Able to divide rapidly in 2nd contact of a pathogen
T regulator cells
Suppress the immune system. Stop immune response once pathogen is killed. Protects self antigens
Plasma cells
Produce antibodies. Only live for a few days but produce around 2000 antibodies per second while active
B effector cells
Divide to form plasma cell clones
B memory cells
Programmed to remember specific antigens and enable the body to make rapid responses when encountered a 2nd time
Antigen presenting cell (APC)
Cell breaking down pathogens and presents cellular fragments on their surface for detection by other immune cells
Clonal selection
The point at which the B cell with the correct antibody to overcome a particular antigen is selected for cloning
Clonal expansion
Activated B cell divided by mitosis to give clones of plasma cells and B memory cells.
Primary immune response
Cloned plasma cells produce antibodies that fit antigens on surface of pathogen. Bind to antigens and disable them. Can also act as opsonins or agglutinins
Secondary immune response
When plasma cell clones are produced in a secondary interaction with a pathogen due to the presence of B memory cells produced by some cloned B cells from the initial interaction
Autoimmune disease
When the immune system stops recognising ‘self’ cells and starts to attack itself
