Functions of phospholipids

 Functions of phospholipids

1. Essential constituent of all cells- In the form of element constant phospholipids constitute an essential part of cell protoplasm.

2. Relation with cell function- It has been shown that the phospholipid content of an organ varies in direct proportion to the degree of its activity. From this fact it has been suggested that the phospholipid content of a tissue is intimately related to cell function and may be regarded as an index of the degree of activity of that tissue.

3. Fat digestion and transport- The lecithin contents of bile and food are concerned for the emulsifying action of bile salts upon food fats. It is transported in considerable amount into blood. Lecithin is an important form in which fat form emulsion with H₂O, so transport of fat from cell to cell takes place in the form of phospholipids.

4. Protection and permeability of cells- Being a constant constituent of cell membrane, phospholipids exert a protective action upon the cells and also regulate the passage of various substances across the cell membrane.

3. Relation with tissue oxidation- It has been suggested that the phospholipids being highly unsaturated compounds may act as oxygen carriers in the cell and help in tissue oxidation, Oxygen may be taken up at the unsaturated bonds and under a suitable condition it is released while required for oxidation purposes.

4. Regulation- Phospholipids play a major role in regulating the respiratory group of enzymes-cytochrome complex.

5. Relation with blood clotting- Phospholipid has a major role in the reaction sequence leading to the formation of blood clot. It has also been noted that rise in blood phospholipid concentration causes depression of fibrinolytic mechanism and reduces the tissue-activating factor VIII concerned for coagulation and stimulates the synthesis of prothrombinase.

7. Donors of phosphate group Phospholipids donate phosphate group for various reactions in the body.

8. Carriers in active transport. It has been suggested that phospholipids act as carriers for the transport of substances, e.g., hormones, enzymes, mucin, etc. through cell membrane.