Lysosomes

• Lysosomes


  Organelles that contain powerful digestive enzymes and have an acidic internal fluid
• Lysosomes


  • Contain powerful digestive enzymes such as proteases
  • Have an acidic internal fluid due to the optimum pH of the lysosomal enzymes
• Phagocytosis by white blood cells


  1. White blood cell forms a vacuole around bacteria (phagosome)

  2. Lysosomes fuse with the phagosome

  3. Lysosomal enzymes digest the bacteria

  4. Soluble digestion products pass into the cytoplasm
• Degradation of damaged or unwanted organelles


  1. Organelle is surrounded by a vacuole

  2. Lysosomes fuse with the vacuole membrane

  3. Lysosomal enzymes digest the organelle

  4. Digestion products are absorbed into the cytoplasm and can be reused
• Exocytosis of lysosomal enzymes

  1. Lysosomes transfer their enzymes outside of the cell

  2. To digest and remove unwanted proteins or dead cells
• Lysosomes play a key role in phagocytosis in white blood cells
• Lysosomes can be used to destroy organelles that are damaged or no longer functional
• Lysosomes can transfer their enzymes outside of the cell by exocytosis