B-lymphocytes and antibodies Flashcards
what is the role of B lymphocytes?
- they produce antibodies tp protect us from infection
- they bind to a virus and which prevents it from entering a normal cell and causing infection
what are the two types of B cells?
- B memory cells
- B plasma cells
where are B lymphocytes made?
made in the bone marrow and mature in the spleen
which B cells are long and short lived?
B memory cells are long lived whereas B plasma cells are short lived
what is the role of B memory cells?
they remember particular antigens so they can be recognised if they appear in the body again to fight against them.
what is the role of B plasma cells?
they secrete antibodies specific to the antigen to destroy specific pathogens to prevent further harm to the body.
what is agglutination and its purpose?
- the clumping together of pathogens
- this prevents them from going on to infect more cells
- also makes it easier for phagocytes to engulf multiple pathogens
what are the different ways antibodies can act?
- agglutination
- aid phagocytosis
- neutralization
how do antibodies aid phagocytosis?
- phagocytes can easily recognise antigen-antibody complexes
- antibody heavy chain binds to the surface
- allows engulfment
how does neutralization occur?
antibodies bind to attachment proteins on the virus - this stops the virus particles from being able to bind to host cells.
what is the purpose of the receptor binding site (in the structure of an antibody)
they bind to receptors on B cells
describe the function of antibodies
- they bind pathogens together in agglutination
- this allows phagocytes to engulf many pathogens at once
what is an antibody?
protein secreted by B lymphocytes with complementary shaped receptors to bind to specific antigen
describe the structure of an antibody?
- the constant region is made of 2 heavy and 2 light polypeptide chains
- chains are held together by disulphide bridges.
- variable region provides a binding site to form an antigen-antibody complex
