Which of the following is NOT one of the regions of immunoglobulin fragments?

Immunoglobulins, or antibodies, consist of distinct structural regions that define their function and binding capabilities. The primary regions of immunoglobulin fragments include the FAB (Fragment Antigen-Binding) region, which is responsible for binding to antigens, and the FC (Fragment Crystallizable) region, which interacts with immune cells and other components of the immune system. The hinge region, which connects these two fragments, provides flexibility and allows the antibody to effectively bind to antigens, enhancing its functionality.

The choice that is not a recognized region of immunoglobulin fragments is "Alpha." While the term might be associated with different aspects of immunology, such as alpha chains in certain antibody classes or subclasses, it does not refer to a distinct region of immunoglobulin structure in the context of fragments like FAB, FC, or hinge regions. Thus, "Alpha" does not fit within the established classifications of immunoglobulin fragments.