antibodies

• antibody structure?

  four polypeptide chains, a variable region, binding site, constant regions, tertiary structure
• what type of polypeptide chains are there?

  two heavy and two light
• how man antigens can one antibody bind to?

  two
• how do antibodies work?

  agglutination, neutralising toxins, preventing viruses from entering
• agglutination?

  antibodies bind to antigens and cause them to clump, and they are then destroyed by phagocytosis
• strength of agglutination?

  clumps mean more phagocytes are destroyed at once
• preventing viruses from entering host cells?

  viruses have spike proteins which bind to receptors which then allow them entry - antibodies bind to the viruses to stop them from doing that
• what is antigenic variation?

  pathogens forming different strains which have different antigens
• limitation of antigenic variation?

  if reinfected a second time, memory cells dont recognise the antigen and wont activate the antibodies
• examples of antigenic variability?

  influenza virus, HIV