1. phagocytosis

• phagocyte


  type of white blood cell that carries out phagocytosis
• 1. phagocyte recognises antigens on a pathogen
• 2. cytoplasm of phagocyte engulfs pathogen
• 3. pathogen is now contained in a phagosome
• 4. lysosome fuses with the phagosome. the enzyme breaks down the pathogen
• 5. phagocyte presents the pathogens antigens. it sticks to antigens on its surface to activate other immune system cells so is actign as an antigen-presenting cell
• neutrophils

  type of phagocyte. the 1st White blood cells to respond to a pathogen in the body. they move to the wound in response to signals from cytokines
• cytokines

  proteins that act as messenger molecules released by cells at the site of a wound
• lysosome


  organelle that contains digestive enzymes
• opsonin


  hide negative charge on pathogens membrane so its easier for the negatively charged phagocyte to get closer
• 1. phagocyte recognises antigens on pathogen
  2. cytoplasm of phagocyte engulfs pathogen
  3. pathogen is now contained in a phagosome in a phagocytes cytoplasm
  4. lysosome fuses with phagosome and breaks down pathogen
  5. phagocyte presents pathogens antigens sticking them on its surface to activate other immune system cells