Antibodies Intro Flashcards
What are antibodies?
Glycoproteins produced by B cells that bind specifically to antigens and target them for destruction
What are the basic components of an antibody?
Two identical heavy chains and two identical light chains held together by disulfide bonds
What are the two functional regions of an antibody?
Fab region that binds antigen and Fc region that interacts with the immune system
What is the role of the hinge region in an antibody?
Provides flexibility for binding multiple antigens
What are variable and constant regions in an antibody?
Variable regions bind to antigens while constant regions determine the antibody class and immune system interactions
What are hypervariable regions HVRs?
Specific parts of the variable regions that bind to antigens also known as complementarity-determining regions CDRs
What is an antigen?
A molecule that triggers an immune response by generating antibodies
What is an epitope?
The specific part of the antigen that an antibody binds to
How do antibodies bind antigens?
Through non-covalent interactions like hydrogen bonds ionic bonds and Van der Waals forces
What is antibody affinity?
The strength of interaction between a single antigen binding site and its antigen
What is antibody avidity?
The overall strength of binding between an antibody and a multivalent antigen
How do IgG and IgM differ in binding strength?
IgG’s bivalency increases avidity by about 10^4 while IgM’s pentameric structure increases it by about 10^7
What does divalent mean in relation to antibodies?
It refers to antibodies like IgG having two antigen binding sites
What are multimeric antigens?
Antigens with multiple or repeated epitopes
What are the key molecular forces in antigen-antibody interactions?
Hydrogen bonds ionic bonds hydrophobic interactions and Van der Waals forces
