Category: Biology Second Paper

Endoplasmic reticulum is found in almost all cells. They are most abundant in the liver, pancreas and endocrine glands. It extends from the nuclear membrane to the cell membrane. It is attached to the nuclear membrane. Mammalian red blood cells, spermatizoa, and sperm lack reticulum.

In 1897, scientist Gorniar observed the lattice-like structure in cells with the help of a light microscope and named them argestoplasm. In 1945, scientist Keith R. Porter and his colleagues Albert Claude and Ernest F. Fullam first discovered it from liver cells. Endoplasmic reticulum was named by scientist Keith R. Porter in 1953. In 1969, scientists Porter, Claude and Fullam described the detailed structure of endoplasmic reticulum from liver cells.

Endoplasmic reticulum is derived from the Greek word endo meaning inside, plasmic meaning plasma and reticulum meaning mesh. Endoplasmic reticulum means endoplasmic reticulum. Endoplasmic reticulum is a branched reticular hollow tube located in the cytoplasm of the cell. Small parts of the endoplasmic reticulum break off to form microsomes.

In hostile environment, intense feeding occurs. At this time the lysosome wall ruptures and the enzymes come out. This enzyme destroys other small parts of the cell. This process is called autophagy. Thus all cells can be digested. This is called autolysis. Lysosomal nuclease enzymes (DNA-ase, RNA-ase) cause blood cancer and thyroxine hormone causes hepatitis and polynephritis. Lysosome enzymes cause about 20 types of congenital diseases or storage diseases. As a result, all cells can be destroyed. For these reasons, lysosomes are called suicidal sacs.

1. Enzyme content: Lysosomes contain 40-50 types of enzymes. Nuclease (DNA-ase, RNA-ase), acid phosphatase, aryl phosphatase, acid lipase, phospholipase, esterase, sucrase, sulfatase, dextronase, lysozyme, collagenase etc. Enzymes are active in acidic environment.
2. Intracellular Metabolism: Lysosomes participate in the intracellular metabolism of cells.
3. Germ-eating: Germs are eaten by the process of pinocytosis and phagocytosis.
4. Autolysis: During acute digestion, the cell wall ruptures and enzymes are released to destroy other organelles. This is called autolysis.
5. Suicide Squad: Autolysis destroys useless body cells. Finally the whole body is destroyed. So it is called suicidal bag or squad.
6. Cell Division: Lysosomes stimulate mitosis in cell division. Helps break down the nuclear membrane.
7. Hormone secretion: It helps in hormone secretion.
8. Metabolism: Lysosomes play a role in the transformation of organisms. Extinction of body parts, especially the frog’s tail.
9. Heterophagy: Enzymes in lysosomes oxidize food and bacteria. This process is called heterophagy.
10. Metabolism: Enzymes in lysosomes convert proteins into dipeptides and sugars into monosaccharides. They produce keratin for cells.
11. Enzyme action: Spermlysin (hyaluronidase) enzyme is secreted from sperm lysosomes. Spermlysin dissolves the ovum wall to form the entrance. It binds the dissolving enzymes so that other cells are protected.
12. Body Defense: Lysosomes in white blood cells help in body defense.
13. Keratin production: Lysosomes produce keratin for the cells.
14. Bone formation: Enzymes released from lysosomes play a special role during bone formation from cartilage.
15. Cell membrane destruction: Golgibodies help in cell and nuclear membrane breakdown. It contains phosphatase enzyme which dissolves tissue.
16. Diseases: Nuclease enzyme released from lysosome causes blood cancer and thyroxine hormone causes hepatitis and polynephritis. Cartilage wears down in rheumatoid arthritis due to the action of lysosomal enzymes.

Lysosomes contain 40-50 types of enzymes. The main enzymes are – nuclease (DNA-ase, RNA-ase), acid phosphatase, aryl phosphatase, acid lipase, phospholipase, esterase, sucrase, sulfatase, dextronase, lysozyme, collagenase etc. Enzymes work in acidic environment. Its coat is composed of lipids and proteins. It contains a small amount of sugar.

Physical structure of lysosome
Lysosomes are small spherical or circular organelles. A large number of hydrolytic enzymes are enveloped to form lysosomes. Each lysosome is surrounded by a two-layered membrane. But the coating of Spherosome or Oleosome is multi-layered. The coating is made up of lipoproteins. Lysosomes are the largest in kidney cells. Their diameter is 0.2-0.8 millimicron. Its vacuoles are filled with fluid. Lysosome coat contains stabilizers and labilizers. Stabilizer maintains the stability of the lysosomal membrane. As a result cortisone, cholesterol, heparin etc. cannot be released. That is, the stabilizer does not allow the enzyme to leave the lysosome. Labilizer disrupts the stability of the lysosomal membrane. As a result, testosterone, progesterone, vitamin-A, vitamin-B, vitamin-K etc. can be released. That is, the labilizer allows the enzyme to escape from the lysosome.

There are two types of lysosomes. Primary lysosomes and secondary lysosomes. Lysosomes that arise from Golgibodies are called primary lysosomes. Primary lysosomes fuse to form secondary lysosomes.

Lysosomes originate from endoplasmic reticulum and Golgibodies. Lysosomes are formed by the end of the cyst of the Golgi body.

Almost all animal cells contain lysosomes. Lysosomes are most abundant in white blood cells, liver cells, lung cells, kidney cells, etc. RBC, yeast and most plant cells do not contain lysosomes. Recently lysosomes have been discovered in plant cells. Lysosomes in plant cells are called Spherosome or Oleosome. Lysosomes are found in onion seeds, bhutra and tobacco cells. Lysosomes have been found in some thallophytes plants.