Immunoglobulins Flashcards

Immunoglobulins Structure and Function

Question	Answer		Article
What are immunoglobulins also known as?	Antibodies		Link to Article
How many domains does the heavy chain have?	1 variable domain 3 or 4 constant domains		Link to Article
How many domains does the light chain have?	1 variable domain 1 constant domain		Link to Article
What are hypervariable domains?	Folded pockets of the variable domain into which antibody can bind Different antibodies have different amino acid sequences within the three variable domains		Link to Article
What does Fab stand for and from which chain is it generated?	Fragment associated with antigen binding Light chain		Link to Article
What does Fc stand for and from which chain is it generated?	Constant fragment Heavy chain		Link to Article
What does the Fc fragment do?	Mediates phagocytosis Triggers inflammation Targets Ig to certain tissues		Link to Article
What are the four major effects of antibodies?	Blockage and agglutination Promotion of phagocytosis Degranulation of mast cells/eosinophils Complement Fixation		Link to Article

Classes of Immunoglobulin

Question	Answer		Article
How do the five classes of immunoglobulins vary from each other?	They each have a different composition to their heavy chains		Link to Article
IgA is specially adapted for function at which type of surface?	Mucosal surfaces		Link to Article
True or False: IgA is a monomer	False IgA is a dimer		Link to Article
What are the functions of IgA?	Prevents agents from adhering to the epithelial surfaces as it binds to foreign antigen Resists proteolytic digestion so can function in the gut Does not activate the complement system so helps to preserve mucosal integrity		Link to Article
In which species has IgD been identified?	Ruminants Pigs Dogs Rodents		Link to Article
What is the main function of IgD?	Helps B cell development		Link to Article
True or False: IgE is not a soluble antibody?	True		Link to Article
What are the functions of IgE?	Triggers acute inflammation by causing degranulation Involved in type I hypersensitivity reactions Involved in producing immunity to parasitic worms and nematode parasites		Link to Article
True or False: IgG is the smallest antibody and can easily leave the plasma and enter tissue?	True		Link to Article
Where is IgG produced?	Bone marrow Spleen Lymph nodes		Link to Article
What is the function of IgG?	Activates the classical pathway of the complement cascade Can act as targets for macrophages, eosinophils and [[Neutrophils		Link to Article
True or False: IgM is a monomer	True But it is secreted as a pentamer		Link to Article
IgM is five times larger than most other antibodies. What effect does this have on its function?	Cannot cross the placenta Does not diffuse quickly or enter tissues readily Its concentration in extracellular fluid and lymph is low		Link to Article
What are the main functions of IgM?	Complement activation Agglutination Opsonisation Virus neutralisation		Link to Article

Immunoglobulins Variation

Question	Answer		Article
Which genes code for the immunoglobulin subtypes and on which chain are they located?	IGH genes Heavy chain		Link to Article
Complete the sentences about IgG subtypes: Humans and rodents have ??? IgG subtypes. Dogs have ??? IgG subtypes. Ruminats have ??? IgG subtypes.	four three three or four		Link to Article
What are allotypes?	Differences in immunoglobulins between individuals of a particular species Allotypes are inheritable		Link to Article
What are idiotypes?	Variations in the sequences of amino acids in the variable regions of the light and heavy chains		Link to Article
What is immunoglobulin heavy chain switching?	After antigenic exposure the IgM+ B-cells differentiate Only after direct influence of T cells Other classes of immunoglobluins are synthesised The same varibale domains are kept		Link to Article
How do different classes of antibody differ from each other?	Size Charge Amino acid composition Associated carbohydrate Function		Link to Article

Originally funded by the RVC Jim Bee Award 2007