Which of the following is known as a digestive organelle of the cells:
Lysosomes are spherical bodies that are enclosed by a single membrane in the cytoplasm of a cell. They and are not seen under a light microscope. Lysosomes are produced by the Golgi apparatus and contain nearly 100 types of hydrolytic enzymes. Dr. Christian de Duve got a Nobel Prize for demonstrating lysosomes in 1974. The most common hydrolytic enzymes are lipase, amylase, protease, nuclease, etc. But, acid phosphatase is the characteristic feature of lysosome. They are involved in the digestion of extracellular substances including organisms that are brought into the cell and also help in digestion of other cellular components.
These enzymes work well in acidic pH. The size of lysosomes varies from 0.1μm to 1.2 μm. These lysosomes are also called as " suicide bags" / "Digestive organelle of the cell"/ "Little stomach of the cell" because of their function.
Types of lysosomes base on stages of development:
1. Primary lysosome:
These are newly formed lysosomes from the Golgi apparatus. They contain all the hydrolytic enzymes without any activity.
2. Secondary lysosome:
Primary lysosome when fuses with the structures that are to be digested by releasing the enzymes are known as secondary lysosomes. They are also referred to as phagosomes, digestive vacuoles or autophagic vacuoles depending on the origin of the material to be digested.
3. Residual bodies:
It the lysosome that has lost its enzymatic capacity and contains undigested residues or debris-filled vacuoles. residual bodies are also called as tertiary lysosomes. Residual bodies are normal feature of a cell ageing.
Eg: lipofuscin pigments or age pigments