Immunoglobulins and Antibody Functions

These flashcards cover key concepts related to antibodies and their functions, including types of immunoglobulins, structures, and roles in the immune response.

Antibodies

Glycoproteins that bind antigens with high specificity and affinity.

Immunoglobulins

Another term for antibodies, often used interchangeably.

Fab fragment

The antigen binding fragment, comprising the N terminal half of the heavy chain and all of the light chain.

V-regions

Segments of highly variable sequences in antibodies that determine specificity.

CDRs

Complementarity determining regions that are responsible for the binding site of immunoglobulins.

Kappa light chains

One type of light chain found in antibodies, accounting for 60% of light chains in humans.

Lambda light chains

One type of light chain found in antibodies, accounting for 40% of light chains in humans.

Isotype

Any of the five different constant regions in heavy chains that define the antibody class.

IgG

The most abundant class of antibody in serum, constituting about 80% of total serum immunoglobulin.

IgM

An antibody class representing 5-10% of total serum immunoglobulin, important in primary immune responses.

IgA

An antibody class constituting 10-15% of total serum immunoglobulin and predominant in external secretions.

IgE

An antibody class with a low serum concentration, involved in allergic reactions.

IgD

An antibody present in low serum amounts, functioning as a marker for B-cell activation.