7: Antibodies

Question 1

four strategies antibodies can use to ensure a pathogen is stopped from harming the host

Answer 1

1. neutralisation
2. agglutination
3. complement activation
4. opsonisation

Question 2

neutralisation - antibodies

Answer 2

antibodies bind to + coat pathogens, blocking their activity

Question 3

agglutination - antibodies

Answer 3

neutralised pathogens clump together + are surrounded by thousands of antibodies

Question 4

complement activation - antibodies

Answer 4

bound antibodies activate a cascade of complement proteins

• complement protein binds to antigen-antibody complex + activated
• C3a fragment attract phagocytes to the area + stimulates inflammation, C3b fragment binds to surface of pathogen (+ tags for destruction)

Question 5

opsonisation

Answer 5

bound antibodies ‘tag’ pathogens for destruction, making it easier for phagocytes to locate them