Lysosomes. Coloured high resolution scanning electron micrograph (SEM) of two lysosomes in a pancreatic acinar cell. Lysosomes (rounded, centre) are small spherical vesicles. They are bound by a single membrane (clearest on lower lysosome) and contain a concentrated mixture of digestive enzymes. These enzymes are used to destroy redundant cell organelles or damaged molecules from within or outside the cell. The organelle or molecule becomes enclosed in a membrane of the lysosome and is digested. Material probably representing partially digested cell organelles can be seen in each lysosome.