Lysosomes : Functions Of Lysosome Organelle
March 16, 2010 in Cell
The cytoplasm of an animal cell contains several small, irregular or spherical shaped membrane bound cell vesicles. These are called as ‘lysosomes’.
The lysosomes are originated from golgi apparatus and contain numerous hydrolytic enzymes. The enzymes can range up to 50. Example- Acid phosphatase. They contain hydrolytic enzymes for intracellular and extracellular digestion.
Functions Of Lysosomes:
Lysosomes perform some important functions of digestion.
They digest the material taken in by endocytosis-
- endocytosis
- phagocytosis
- pinocytosis- parts of the cell by autophagy and extracellular substances.
- They contain powerful destructive enzymes which can digest all organic material and hence are called as “digestive bags”.
- Their presence in white blood cells causes digestion of bacteria and viruses.
- Lysosomes digest fats, proteins and glycogen in the cytoplasm and supplies energy to the cell.
- Lysosomes are also capable of digesting worn out cells and cell organelles. Hence, these are also called as “suicidal bag”.
The lysosome is labeled in the upper left.
Composition Of Lysosomes:
- It has a high acidic medium of pH 5.0 and this acidification depends on ATP- dependent proton pumps.
- These pumps are present in the lysosome membrane and this accumulates protons inside the lysosomes.
Types Of Lysosomes-
Lysomsomes exhibit great great polymorphism. There are four types of Lysosomes-
- Primary lysosomes- these are storage granules.
- Secondary lysosomes- these are digestive granules.
- Residual bodies
- Autophagic vacuoles
The lysosomes of plant cells are membrane bounded storage granules containing hydrolytic digestive enzymes. Example- large vacuoles of parenchymatous cells of corn seedlings, protein and aleurone bodies and starch granules of cereal and other seeds.