Antigens Flashcards
What are antigens?
Molecules (usually proteins) that can generate an immune response when detected by the body
Where are antigens usually found?
On the surface of cells
What are foreign antigens?
Antigens which aren’t normally found in the body
Immune system responds to these
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?
Organisms that cause disease
E.g. bacteria, viruses and fungi
Where are antigens found on pathogens?
On the surface
How does a pathogen trigger a response from the immune system?
The antigens on the surface are identified as foreign by the immune system cells, which then respond to destroy the pathogen
What are abnormal body cells?
Cancerous or pathogen-infected cells that have abnormal antigens on their surface, which trigger an immune response
What are toxins?
Poisons
Molecules, not cells
What are some toxins produced by?
Bacteria
Can the immune system respond to toxins?
Yes
As well as the pathogens that release them
How do cells received from another person trigger an immune response?
The cells received will have antigens that are different to your own (unless donor is genetically identical to you)
Foreign antigens trigger an immune response
What can an immune response do if you have an organ transplant?
Can lead to rejection of transplanted organs if drugs aren’t taken to suppress the recipient’s immune system
