Which region of the immunoglobulin molecule can bind antigen?

Which region of the immunoglobulin molecule can bind antigen?

• A. Fab
• B. Fc
• C. CL
• D. CH

Answer: (A)

The region of the immunoglobulin molecule that binds antigen is known as the Fab region. This area is composed of the variable regions of both the heavy and light chains and is responsible for the specific recognition and binding to particular antigens. The structure of the Fab region allows for the diversity needed to recognize a vast array of different antigens, making it critical for the immune response. In contrast, the Fc region, which is composed of the constant part of the heavy chain, interacts with cell surface receptors and complement proteins but does not directly bind to antigens. The CL (Constant Light) region and CH (Constant Heavy) regions contribute to the overall structure and function of the immunoglobulin but are not directly involved in antigen recognition. Therefore, understanding the roles of these various regions is crucial in immunology, particularly when discussing how antibodies function in the immune system.

The region of the immunoglobulin molecule that binds antigen is known as the Fab region. This area is composed of the variable regions of both the heavy and light chains and is responsible for the specific recognition and binding to particular antigens. The structure of the Fab region allows for the diversity needed to recognize a vast array of different antigens, making it critical for the immune response.

In contrast, the Fc region, which is composed of the constant part of the heavy chain, interacts with cell surface receptors and complement proteins but does not directly bind to antigens. The CL (Constant Light) region and CH (Constant Heavy) regions contribute to the overall structure and function of the immunoglobulin but are not directly involved in antigen recognition. Therefore, understanding the roles of these various regions is crucial in immunology, particularly when discussing how antibodies function in the immune system.