Antibodies

Question 1

What do foreign antigens do?

Answer 1

Antigens stimulate immune response. Foreign antigens stimulate antibody production. Protein/Glycoprotein in/on plasma membrane.

Question 2

What are antibodies?

Answer 2

Antibodies are protein molecules that can identify and neutralise antigens.

Question 3

What can Antibodies do to Antigens?

Answer 3

Antibodies have a complementary shape to antigens. Attach to render them harmless.

Question 4

What is the antibody structure?

Answer 4

 Four polypeptide chains, held by disulphide bridges.
 Constant region to attach to phagocytic cells, and helps for phagocytosis.
 Variable region, result of amino acid sequence – shape of variable region is complementary to shape of antigen, and can bind to antigen.
 Hinge regions which allow a certain degree of flexibility – Y-shaped branches for movement.

Question 5

What is Neutralisation?

Answer 5

Neutralisation is antibodies covering the pathogen binding sites prevent the pathogen binding to a host cell and entering the cell.

Question 6

What is Agglutination?

Answer 6

Agglutination is a large antibody which can bind many pathogens together, too large collectively, to enter the host cell.