Antibody Structure and Function Flashcards
Fraction of plasma where antibodies are found
Gamma globulin fraction
Immunoglobulin
Protein produced in immune responses
Usually used interchangeably with antibody
Antibody structure
2 heavy chains and 2 light chains, both held together by disulfide bonds
“Y-like” structure
Variable region
Ends of light and heavy chains
Gives antibody specificity for binding antigen
Hypervariable region
Antigen binding site on antibody
Constant region
Bottom part of antibody: doesn't bind antigen Sequence determines class of antibody
Hinge region
Middle of antibody
Makes antibody more flexible
Antibodies’ 2 roles
Antigen receptor (variable domain) Elimination/inactivation of foreign antigen or cell that bears antigen (constant domain function)
Where antibodies are made
Plasma cells (B cells) Lymphoid tissues
Complementarity determining region (CDR)
Antigen binding site on hypervariable region of antibody
Isotypic determinant
Constant region specific
Common across species, but recognized as foreign by other species
Allotypic determinant
Constant region specific
Recognized as foreign across same members of species (some members have it, but others don’t)
Idiotypic determinant
Variable region specific
Specific to individual
Primary response
Slow in onset
Low in magnitude
Short lived
Mediated by IgM
Secondary response
Rapid in onset
High in magnitude
Long lived
Mediated by IgG
