Lysosomes are small membrane bound vesicular bodies present in cells. These organelles perform intracellular digestion. Lysosomes occur in all animal cells but not so common in plant cells. Plant lysosomes contain reserve food materials besides the enzymes.They are of three types.
1. Vacuoles: These are rounded sac containing a variety of hydrolytic enzymes.
2. Spherosomes: They are spherical membrane bound lipids and proteins.
3. Aleurone grains: These are also spherical membrane bound bodies containing proteins. These are found in cells of endosperms and cotyledons of seeds