Antibodies and the Primary and Secondary Immune Response

Question 1

What is the structure of an antibody?

Answer 1

• Antibodies are proteins with a specific primary, secondary and tertiary structure
• Antibodies have a variable region and a constant region which are joined by a hinge and held together by disulphide bridges
• The antibodies tertiary structure is responsible for the specific variable region which allows the antibody to form antibody-antigen complexes with its complementary antigen

Question 2

What happens in the primary immune response?

Answer 2

• First immune response
• Slow because immune response has to under go phagocytosis -> T-cells -> B-cells -> plasma cells and then the production of antibodies
• Whilst the immune response is taking place the pathogen is able to multiply and you feel symptoms
• When infection is over you save some plasma cells as memory cells incase of a secondary infection

Question 3

What happens in a secondary immune response?

Answer 3

• The same pathogen with the same antigen infects you
• The immune response is faster and stronger because you already have the memory B and T-cells which can divide and carry out the humeral and cellular responses in order to kill pathogens (T) and produce antibodies (B)
• Because the pathogen has less time to replicate you fell no symptoms
• Antigenic variation and various pathogen strains can prevent this