ANTIBODIES

Question 1

what are antibodies

Answer 1

y shaped proteins (each chain has a tertiary structure)
made by plasma cells
soluble in body fluids
2 identical binding sites complementary to a specific antigen
form an antigen - antibody complex
also known as immunoglobulins

Question 2

structure of antibodies

Answer 2

4 polypeptide chains held by disulfide bridges
constant region (same structure as a sequence of amino acids in all antibodies) allowing it to attach to phagocytic cells
variable region (complementary to a specific antigen depending on its amino acid sequence allowing it to bind to a antigen
hinge region allowing it to flex and bind to more than one antigen

Question 3

what 2 things do antibodies do

Answer 3

neutralisation
agglutination

Question 4

what is antibody neutralisation

Answer 4

pathogen may use its antigen to bind to host cell. this can be prevented by an antibody binding to the antigen first

Question 5

what is antibody agglutination

Answer 5

some antibodies can bind to antigens on multiple pathogens clumping pathogens together preventing them from entering host cells