1. Presented by
Surya Pratap Singh
M.Sc. Life Sciences
Central University of Gujarat

2. INTRODUCTION
• Lysosomes discovered by the cytologist
Christian de Duve in the 1960.
• Lysosomes are spherical organelles that
contain enzymes . They break up food so it is
easier to digest. They are found in animal
cells, while in yeast and plants .
• Lysosomes are common in animal cells but
rare in plant cells contain hydrolytic enzymes
necessary for intracellular digestion.

3. STRUCTURES OF LYSOSOME

4. • Lysosomes are spherical structures bounded by a
single unit membrane.
• The size of lysosomes varies from 0.2 to 0.8 nm.
• lysosomal membranes are sensitive to many
labilizers and stabilizers

6. ENZYMES OF LYSOSOMES
• Lysosomes
are
membrane
enclosed
compartments filled with soluble hydrolytic
enzymes.
•
Lysosomes contain about 40 types of
hydrolytic enzymes, including proteases,
nucleases,
glycosidases,
lipases,
phospolipases, phosphatases, and sulfatases.
• Lysosome provides by maintanining a pH
about 4.5 to 5.0.

8. LYSOSOMES ARE HETROGENEOUS
• The hetrogeneity of lysosomal morphology
contrasts with realatively uniform structures
of most other cell organelles.
• The late endosomes contain material
received from both the plasma membrane by
endocytosis
and
newly
synthesized
lysosomal hydrolases.
• Late endosomes fuse
lysosomes
to
form
endolysosomes.
with preexisting
structures
that

9. • Endolysosomes fuse and form lysosomes.
• This reason lysosomes are sometimes
view as a hetrogeneous.

10. PLANT AND FUNGAL VACUOLES ARE SIMILAR TO
LYSOSOMES
• Plant and fungal cells contain one or several very
large fluid-filled vesicles called vacuoles.
• It is related to animal cell lysosomes and
contain a variety of hydrolytic enzymes.
• The plant vacuole can act as a storage organelle
for both nutrients and waste products.
• The vacuole is important as a homeostatic
device.

11. • All these hydrolytic enzymes are produced
in the endoplasmic reticulum, and to some
extent in cytoplasm are transported and
processed through the Golgi apparatus.
• Lysosomal enzymes are synthesized in the
cytosol and the endoplasmic reticulum,
where they receive a mannose-6-phosphate
tag that targets them for the lysosome.
• If the lysosomal enzymes do not reach the
target it causes inclusion-cell disease,
resulting in accumulation of waste within
these organelles

13. THE FUNCTION OF LYSOSOMES
• A lysosome is a membrane bag containing
digestive enzymes.
• For digest food, the lysosome membrane
fuses with the membrane of a food vacuole
and squirts the enzymes inside.
• The digested food can then diffuse through
the vacuole membrane and enter the cell to
be used for energy or growth.
• Lysosomes are sometimes called "suicide bags’’

15. • Lysosomes are the cells' garbage disposal
system. They are used for the digestion of
macromolecules from phagocytosis.
• Lysosome's pick up foreign invaders such
as bacteria, food and old organelles and
break them into small pieces that can
hopefully be used again.
• Autophagy may also lead to autophagic
cell death, a form of programmed selfdestruction, or autolysis of the cell, which
means that the cell is digesting itself.

17. CONCLUSION
• Lysosmes are specialized for the intracellular
digestion of macromolecules.
• These enzymes work only at low pH (highly
acidic) levels.
• Uncontrolled release of lysosome contents into the
cytoplasm can also cause cell death (necrosis).