Antibodies and Antigens

Question 1

What are antigens

Answer 1

proteins found on the surface of cells which trigger an immune response

Question 2

structure of an Antibodies

Answer 2

• a glycoproteins with 4 polypeptide chains
• 2 long heavy chains and 2 short light chains
• disulphide bonds between each long chain
• antigen binding side has an amino acid sequence specific to antigens

Question 3

what are makes antibodies

Answer 3

B lymphocytes/ plasma cells

Question 4

Roles of antibodies in the immune response

Answer 4

1. causes agglutination which clumps together pathogens to stop them from reproducing sp phagocytes can engulf them
2. prevent pathogens binding to cells by blocking the cell surface receptors the pathogen needs when binding to a host cell
3. neutralise toxins by binding t them and preventing them affecting our cells

Question 5

Production of Antibodies

Answer 5

1. antigen on a pathogen binds to B cells complementary receptor
2. pathogen is engulfed and digested by B cell and becomes an APC
3. an activated T-helper cell binds to B cell and releases cytokines which activates B cell to undergo mitosis
4. B cell splits into B-memory cells and B-effector cells
5. B-effector cells then differentiate into plasma cells which then secrete antibodies