Specific Defenses Flashcards
What are antigens made of?
Protein
What are antigens?
Molecules on the surface of cells that
trigger a specific immune response
What are lymphocytes?
andwhat do they do?
The white blood cells involved in the specific immune response.
They respond to specific antigens on invading pathogens
Name the white blood cells that
respond to specific antigens on
invading pathogens
Lymphocytes
Describe the membrane receptors
found on lymphocytes
Lymphocytes have a single type of
membrane receptor, specific for one
antigen
Describe what happens when a lymphocyte receptor binds to an antigen
Repeated lymphocyte division occurs, resulting in a clonal population of identical lymphocytes
Name the two types of
lymphocytes
B-lymphocytes and T-lymphocytes
State the role of B-lymphocytes
They produce specific antibodies
Explain how the structure of anti
bodies helps fight infection
Antibodies have receptor binding sites
which are specific to a particular antigen on a pathogen
What are antibodies made of?
Protein
Describe what happens when
antibodies bind to antigens
The pathogen is inactivated and the
resulting antigen-antibody complex can
then be destroyed by phagocytes
Describe how an allergic reaction
can occur
B-lymphocytes display a hypersensitive
response to a harmless antigen
(e.g. pollen)
State the role of T-lymphocytes
T-lymphocytes destroy infected body
cells by recognising antigens of the
pathogen on the surface of the cell
membrane and inducing apoptosis
Define the term apoptosis
programmed cell death
Describe how apoptosis is brought
about by T-lymphocytes
T-lymphocytes attach to infected cells
and release proteins that diffuse into the
infected cells leading to the release of
self-destructive enzymes which cause cell
death
