Topic 2---C: Cells and The Immune System- 1. Antigens Flashcards
What is an antigen?
Molecules (proteins) that can generate an immune response on a cells surface when detected by the body.
What are the antigens that aren’t normally found in the body called?
Foreign antigens
What do antigens allow the immune system to identify?
- Pathogens
- Abnormal body cells
- Toxins
- Cells from other individuals of the same species
What are pathogens?
These are microorganisms that cause a disease.
They have antigens on their surface.
What are examples of a pathogen?
- Bacteria
- Viruses
- Fungi
What are abnormal body cells?
Cancerous or pathogen-infected cells have abnormal antigens on their surface, which trigger an immune response.
What are toxins?
These are poisons. Some of them are produced by bacteria.
What are cells from other individuals of the same species?
When you receive cells from another person such as an organ transplant, those cells will have some antigens that are different to your own triggering an immune response.
Why do some antigens generate an immune response?
The immune system identifies them as foreign.
