AP BIOLOGY

Detailed explanation-1: -Antigens are markers that tell your body that something is foreign. Your immune cells make antibodies to recognize and destroy harmful antigens. In fact, you can think of antigens as antibody generators. Antibodies are very specific to the antigens they recognize and destroy.

Detailed explanation-2: -Antigens are any substances that the immune system can recognize and that can thus stimulate an immune response. If antigens are perceived as dangerous (for example, if they can cause disease), they can stimulate an immune response in the body.

Detailed explanation-3: -The immune system recognizes invaders by their antigens, which are proteins on the surface of the invading cells (see Figure 1). Every cell or substance has its own specific antigens, and a person’s cells carry “self-antigens” that are unique to that individual.

Detailed explanation-4: -The immune system protects the body from possibly harmful substances by recognizing and responding to antigens. Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria.

Detailed explanation-5: -Antigen recognition by B cells involves direct binding of immunoglobulin to the intact antigen and, as discussed in Section 3-8, antibodies typically bind to the surface of protein antigens, contacting amino acids that are discontinuous in the primary structure but are brought together in the folded protein.