🦠microbiology review
key term - Antigens
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Definition
Antigens are molecules or molecular structures that can be recognized by the immune system, specifically by antibodies, B cells, or T cells. They trigger an immune response when detected in the body.
5 Must Know Facts For Your Next Test
- Antigens are typically proteins or polysaccharides found on the surface of pathogens like bacteria and viruses.
- Each antigen has distinct regions called epitopes that are recognized by specific antibodies.
- Self-antigens are normal molecules of the host's body, whereas non-self antigens originate from external sources like pathogens.
- The immune system uses antigen presentation to detect and respond to foreign antigens via MHC (Major Histocompatibility Complex) molecules.
- Vaccines work by introducing a harmless form of an antigen to stimulate an adaptive immune response without causing disease.
Review Questions
- What types of molecules typically act as antigens?
- How do epitopes relate to antigens and antibodies?
- What role do MHC molecules play in antigen recognition?
