Antigen vs Pathogen
Antigen:
Antigen refers to any substance that can trigger an immune response in the body. It is usually a protein or polysaccharide on the surface of a cell or virus that is recognized by the immune system as foreign.
- **Definition**: Antigen is a substance that can stimulate an immune response.
- **Nature**: Antigens can be proteins, polysaccharides, or other molecules.
- **Recognition**: Antigens are recognized by the immune system as foreign invaders.
- **Response**: When an antigen is detected, the immune system produces antibodies to neutralize it.
Pathogen:
Pathogen is a type of antigen that specifically refers to a disease-causing microorganism. Pathogens can be bacteria, viruses, fungi, or parasites that invade the body and cause illness or infection.
- **Definition**: Pathogen is a type of antigen that causes diseases.
- **Nature**: Pathogens are disease-causing microorganisms like bacteria, viruses, fungi, and parasites.
- **Invasion**: Pathogens invade the body and cause infections or diseases.
- **Immune Response**: When the immune system detects a pathogen, it mounts a defense to eliminate it from the body.
In summary, all pathogens are antigens, but not all antigens are pathogens. Antigens can be harmless substances that trigger an immune response, while pathogens specifically refer to disease-causing agents that invade the body and cause illnesses.