What is the function of the variable region of an antibody molecule?

• A. To facilitate phagocytosis
• B. To activate the complement system
• C. To determine the antibody's class
• D. To bind specifically to antigens

Answer: (D)

Verified step by step guidance

1. Understand that antibodies are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses.
2. Recognize that an antibody molecule consists of two main regions: the constant region and the variable region.
3. The constant region is responsible for mediating the effector functions of the antibody, such as activating the complement system or facilitating phagocytosis.
4. The variable region of an antibody is unique to each antibody and is responsible for binding specifically to antigens. This region is highly diverse, allowing antibodies to recognize a vast array of antigens.
5. Conclude that the primary function of the variable region is to bind specifically to antigens, enabling the immune system to target and neutralize specific pathogens.