Lysosomes are organelles that contain digestive enzymes (acid hydrolases). They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria. The membrane surrounding a lysosome prevents the digestive enzymes inside from destroying the cell.
As it turns out, our tears do contain some magic, namely the powerful enzyme lysozyme. This enzyme is crucial in thwarting bacteria that attempts to enter our body cavities. By destroying the peptidoglycan layer of bacterial cell walls, it serves as a strong chemical defense against bacterial infections.
