Antibodies Flashcards
What are antibodies?
These are proteins with specific binding sites synthesised by B cells.
How does the antibody react with the antigen on the surface of the non-self material?
By binding to the antigen.
How many identical binding sites does each antibody have?
Each antibody has two identical binding sites.
What are the binding sites complementary to?
They are complementary to a specific antigen.
Why is there a massive variety of antibodies?
This is because they are proteins.
How many polypeptide chains are antibodies made up of?
4 polypeptide chains
What are the long chains on one pair of polypeptide chains called?
Heavy chains.
What are the chains of the other pair known as?
They are shorted and known as light chains.
What is formed when an antibody fits very precisely onto a specific antigen?
An antigen-antibody complex.
What is different on different antibodies?
The binding site.
What is the binding site known as?
The variable region.
What does each binding site consist of?
A sequence of amino acids that form a specific 3D shape that binds directly to the antigen.
Why is the rest of the antibody known as?
The constant region.
What does the constant region bind to?
Receptors on cells such as those on B cells.
What is the shape of an antibody like?
It is a Y shape.
Do antibodies destroy antigens directly?
No they don’t.
What do antibodies do to the antigen?
They prepare it for destruction.
What are the two ways in which antibodies assist in the destruction of a bacterial cell?
They cause agglutination of the bacterial cells. In this way clumps of bacterial cells are formed, making it easier for the phagocytes to locate them as they are less spread out within the body.
They serve as markers that stimulate phagocytes to engulf the bacterial cells to which they are attached.
What does each antigen induce?
A different B cell to divide.