Antigen Receptors of Lymphocytes: Structure and Function

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How are the light and heavy chains of an antibody molecule connected?

Each light chain is attached to one heavy chain, and the two heavy chains are attached to each other, all by disulfide bonds.

What are the components of an antibody molecule?

An antibody molecule is composed of four polypeptide chains - two identical heavy (H) chains and two identical light (L) chains.

What is the structure of an Ig domain?

An Ig domain consists of two layers of a β-pleated sheet held together by a disulfide bridge.

How many C domains does a heavy chain of an antibody molecule have?

A heavy chain has three or four C domains. Signup and view all the answers

What are the features of antigen receptors of B and T lymphocytes important for their functions in adaptive immunity?

The antigen receptors of B and T lymphocytes have many similarities in terms of structure and mechanisms of signaling. Signup and view all the answers

What are the fundamental differences in the types of antigenic structures recognized by B cells and T cells?

B cells recognize antigens using antibodies, while T cells recognize antigens using T cell receptors. Signup and view all the answers

What are the three CDRs responsible for antigen recognition in Ig molecules?

V regions Signup and view all the answers

Where is the greatest variability found among the three hypervariable regions in Ig molecules?

CDR3 Signup and view all the answers

What is the fragment of an antibody that contains the portion required for antigen recognition?

Fab (fragment, antigen-binding) Signup and view all the answers

What is the portion of the antibody that tends to crystallize in solution?

Fc (fragment, crystalline) region Signup and view all the answers

What region of the antibody molecule allows the two antigen-binding Fab regions to move independently?

Hinge region Signup and view all the answers

How many identical Fab regions that bind antigen are there in each Ig molecule?

Two Signup and view all the answers

Where is the C-terminal end of the heavy chain anchored in some Ig molecules?

Plasma membrane Signup and view all the answers

How many types of heavy chains are there in Ig molecules?

Five Signup and view all the answers

What are the antigen receptors of naive B lymphocytes?

Membrane-bound IgM and IgD Signup and view all the answers

What happens to the antigen-specific B lymphocyte clone after stimulation by antigen and helper T lymphocytes?

Expand and differentiate Signup and view all the answers