Antibodies and Antigens Flashcards
Antibodies are composed of
four poly peptide chains
what are the two chains that make up the four peptides
two heavy and two light chains
what shape is an antibody
-y-shaped
what is in the y-shaped region
- bilateral symmetry
- two N-terminals
- C-terminal
the N-terminal is
the C-terminal is
antigen binding sites
Constant region
what is an antigen
molecule of microbe that interacte with the antigen binding site
what are the 5 constant regions of
IgG, IgM, IgD, IgA, IgE
what is the regions defined by
heavy chain constant region
what do the constant region mediate
antibody effector functions
IgM,IgG,IgA cause
an activation of complement
IgG and IgE bind to
Fc receptors
IgA can
transport to special sites like the mucosal surface
what is the first antibody produced during immune response
Igm
IgA prevents
attachment of bacteria and viruses to mucosal membrane, picks up secretory components from epithelial cells which protects Fc portion from luminal protease
IgD is expressed
on surface of mature, naive B cells
IgE
binds mast cells and basophils when exposed to allergens and contributes to immunity to parasites by activating Eosinphils
which constant region can cross the placenta
IgG and provides the fetus with immunity
Circulating IgM antibodies are
pentamers with 10 antigen binding sites
Circulating IgA antibodies are
dimers and has 4 antigen binding sites
the varients of IgG are encoded by
4 related gene segments
Fab stands for and what does it determine
fragment antigen binding
determines idiotype
how can fab be used clinically
protease cleavage can seperate antigen binding (Fab) from antibody effector function (Fc)
what is the epitope
precise region of an antigen molecule that interacts with the antigen binding site
one antigen can have
multiple different epitopes
