How Antibodies Defend The Body

Question 1

Agglutination

Answer 1

Each antibody has 2 binding sites, so an antibody can bind to 2 pathogens at the same time. Pathogens clump together. Phagocytes then bind to antibodies and engulf multiple at once.

Question 2

Neutralisation

Answer 2

Anti-toxins bind to the toxins produced by pathogens. This prevents the toxins from affecting human cells so toxins are neutralised.

Question 3

Preventing pathogens binding to cells

Answer 3

When the antibodies bind to the antigens on pathogens they may block the cell surface receptors that pathogens need to bind to host cells.

Question 4

Act as opsonis

Answer 4

Fiat pathogens to facilitate phagocytosis. Phagocytes gave receptors for the constant region of antibodies and by attaching to bacteria the antibodies mark them for destruction.