Antibodies/antigens Flashcards
What are antigens?
Proteins/glycoproteins that are found on the cell surface membrane of pathogens which stimulate an immune response.
Why do antigens have different shapes?
They have different tertiary structures
It means it’s either a different pathogen or the same pathogen with different antigens.
What are antibodies?
Proteins that are produced by B lymphocytes in response to specific antigens. They have complementary shapes to their corresponding antigens.
What are the parts of an antibody?
2 antigen binding sites Hinges Disulfide bonds Variable/constant heavy region Variable/constant light region
What do hinges allow in antibodies?
Flexibility in antigen finding so it can easily bind to 2 antigens
What do the constant regions in antibodies allow?
Phagocytes to recognise them
What are some of the features of the antigen binding sites?
Specific to antigens
Complementary to antigens (variable regions)
Can bind to 2 antigens
What are the 3 things antibodies can do?
Opsonisation
Agglutinisation
Antitoxin
What is opsonisation?
Antibody acts as an opsonin
Antigen binding sites attach to an antigen
The constant region is recognised by a phagocyte and the pathogen is engulfed.
How do antibodies act as an antitoxin?
They attach to toxins so toxins can’t cause any harm in the body.
What is agglutinisation?
A big clump of pathogens form as antibodies attach to 2 pathogens at once so a phagocyte can destroy lots of pathogens at once.
What are antibodies also known as?
Immunoglobulins
