Questions and Answers
What are the 5 major classes of immunoglobulins?
IgM, IgG, IgA, IgE, IgD
What is each class of immunoglobulin determined by?
The constant region of the IG heavy chain
What are the three most abundant classes of immunoglobulins in the serum?
IgM, IgG, and IgA
What is the first molecule made in response to infection?
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What is the role of IgA?
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What is the major class of immunoglobulin found in serum?
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What immunoglobulin plays a role in allergies?
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What is the role of IgD?
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What enzyme is required for both somatic hypermutation and class-switching?
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What are the two types of light chains?
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What is opsonization?
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Study Notes
Classes of Immunoglobulins
- Five major classes of immunoglobulins: IgM, IgG, IgA, IgE, and IgD.
- Immunoglobulin class is determined by the constant region of the heavy chain.
Abundance in Serum
- Three most abundant immunoglobulins in serum: IgM, IgG, IgA.
- IgG is the most prevalent immunoglobulin and the only class capable of crossing the placenta, providing protection to newborns.
Primary Immune Response
- IgM is the first antibody produced in response to infection.
- Exists as a pentamer structure in the circulatory system, plays a crucial role in the primary immune response.
Mucosal Immunity
- IgA is essential for mucosal immunity and is found in secretions across epithelial barriers, such as mucus.
- Unique as it is the only immunoglobulin in breast milk, providing passive immunity to infants.
- Predominantly located on epithelial cell surfaces acting as a neutralizing antibody.
Role of IgG
- IgG is the major immunoglobulin in serum and serves as the primary "workhorse" of the immune system.
- Passively transfers maternal immunity to the fetus through the placental barrier.
Functions of IgE
- Primarily associated with protecting against parasites, functioning on epithelial surfaces.
- Binds to mast cells, triggering allergic reactions due to its high affinity for IgE molecules.
IgD Characteristics
- IgD is predominantly found as a receptor on B cells; it is the only immunoglobulin in a cell-bound form.
Importance of AID
- Activation-induced deaminase (AID) is crucial for both somatic hypermutation and class-switching during immunoglobulin production.
Types of Light Chains
- Immunoglobulins have two types of light chains: kappa and lambda.
Opsonization Process
- Opsonization involves the binding of the Fc portion of IgG antibodies to phagocyte receptors, facilitating the phagocytosis of microorganisms coated with IgG. This mechanism is vital for immune defense.
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Description
Test your knowledge of the five major classes of immunoglobulins with these flashcards. Learn about their characteristics, what determines each class, and which are most abundant in serum. Perfect for students studying immunology or related fields.
