Antibody Action

Question 1

What are the 3 ways that antibodies can act

Answer 1

Agglutination
Aiding phagocytosis
Neutralisation

Question 2

What does agglutination do

Answer 2

Reduces the chances of spreading the pathogen through the body by clumping pathogens together

Question 3

What does aiding phagocytosis help with

Answer 3

It helps phagocytes to easily recognise antigen-antibody complexes
Antibody chains can then bind to the surface so engulfment can happen more often

Question 4

What does neutralisation do

Answer 4

It means antibodies can bind to attachment proteins on viruses
This means virus particles can’t bind to host cells

Question 5

Explain how antibodies lead to the destruction of pathogens

Answer 5

Antibodies bind to antigens on pathogens forming an antigen-antibody complex. This has a specific tertiary structure so the binding site binds to the complementary antigen
Each antibody binds to 2 pathogens at a time causing agglutination (clumping) of pathogens
Antibodies attract phagocytes
Phagocytes bind to to the antibodies and phagocytose many pathogens at once

Question 6

What are antibodies in terms of proteins

Answer 6

Quaternary structure proteins (4 polypeptide chains)

Question 7

What are antibodies secreted by

Answer 7

B lymphocytes

Question 8

What do antibodies bind to? What does this form

Answer 8

Antigens
Antigen - antibody complexes

Question 9

Describe the primary immune response

Answer 9

Antibodies are produced slowly and at a lower concentration
It takes time (around 10 days) for specific B cells to be stimulated and produce specific antibodies
Memory cells are produced

Question 10

Describe the secondary immune response

Answer 10

Antibodies are produced quicker and at a higher concentration
B memory cells rapidly undergo mitosis to produce many plasma cells which produce specific antibodies
Usually takes 2-3 after exposure to the pathogen