Phospholipid Bilayer | Introduction, Structure and Functions

By | July 3, 2019

Phospholipid Bilayer

Phospholipid Definition

Phospholipid Bilayer is basically a special form of lipid molecule which is mainly the major constituent of the Cell Membrane. Fats, Waxes, and Vitamins are the molecules that are Lipids in nature and composed of Lipids. While Phospholipid is comprised of two molecules of Fatty acids, Phosphate Group, and a Glycerol Molecule. Generally, whenever many molecules of Phospholipids are striped up in a straight line, they form a Double Layer which is a vital part of Cell Membranes.

Phospholipid Diagram

Phospholipid Bilayer

Phospholipid Structure

A Phospholipid molecule is comprised of two Fatty Acid tails and Phosphate Group which make its Head. Fatty acids are chemically composed of long chains of Hydrogen and Carbon atoms. While Phosphate groups comprised of a Phosphorus molecule. Four oxygen molecules attached to Phosphate group. Further, Fatty acids long chain and the Phosphate group are attached to the third molecule which is Glycerol.

What Do Phospholipids Do

Phospholipids perform various process inside the organisms. Fatty acids have the ability to form Cell Membranes because the Head of Phosphate group is Hydrophilic. While in contrast, the tails of Fatty Acid tails are Hydrophobic. Hydrophilic is the water-loving while Hydrophobic is water-hating molecules. Due to this, inevitably Fatty Acids assemble themselves in a specific outline within the water because of these Hydrophilic and Hydrophobic properties and Cell Membrane formed.

While Nuclear Envelope is also a membrane which surrounds a Nucleus of Cell’. It is also composed of Phospholipids assembled in a specialized way to form a lipid bilayer. Mitochondria is a Power house s nucleus, is also made up of phospholipids arranged in a lipid bilayer, as is the membrane of mitochondria, the part of the cell that produces energy.

Phospholipids Examples             

  1. Phosphatidylcholine

  2. Phosphatidylserine

  3. Sphingomyelin

  4. Phosphatidylethanolamine

  5. Phosphatidylglycerol

  6. Dihydrosphingomyelin

  7. Ethanolamineplasmalogen

  8. Lysophosphatidylcholine

  9. Phosphatidylinositol

Phospholipid Bilayer

Phospholipid Bilayer

The phospholipid bilayer comprised of two end-to-end phospholipids sheets which assemble from tail to tail order. The Hydrophobic tails attached with each other, establishing the interior side of the membrane. The Polar heads commerce the fluid inside and outside environment of the Cell.

Fatty acids have the ability to form Cell Membranes because the Head of Phosphate group is Hydrophilic. While in contrast, the tails of Fatty Acid tails are Hydrophobic. Hydrophilic is the water-loving while Hydrophobic is water-hating molecules. Due to this, inevitably Fatty Acids assemble themselves in a specific outline within the water because of these Hydrophilic and Hydrophobic properties and Cell Membrane formed.  To create the Cell Membranes, phospholipids arranged themselves next to each other along with their heads on the external of the Cell and their tails are on the interior side of the Cells. While the second layer of Phospholipids correspondingly forms. In which their head pebbledash the Cells exterior side while tails are facing inside.

Due to this, Phospholipids double layer is formed in which Heads of Phosphate group are exteriorly, and tails of Fatty acid tails on the inside. This model is known as the Phospholipid Bilayer Model. It is an integral part of the Cell Membrane.

Phospholipid bilayer work as a Semipermeable Membrane. Lipophilic solutes readily only pass through Phospholipid Bilayer. Due to this characteristic ability, two separate aqueous sections on each side of the membrane is formed. This partition is necessary for biotic functions, as well as cell communication and metabolism.

Phospholipid Bilayer

What is the Function of Phospholipids in the body?

Phospholipid Bilayer

Phospholipids Functions

  1. Phospholipids are the major component of membrane. They are Semi-permeable in nature which means they only allow specific molecules to pass over them in order to enter or exit the cell.
  2. Phospholipids are the major source of energy. They can be fragmented down inside the Cell and utilize for energy purposes.
  3. Phospholipids also are fragmented into minor molecules which are called Chemokines.
  4. Chemokines are vital molecules of the cells which control various cell functions like Protein production, protein transfer to various parts of the body where they are needed. Furthermore, these molecules are present in the lungs and joints where they lubricate the cells and due to this friction will be reduced.
  5. Phospholipids are also used in the Pharmaceutical industry. They play an essential role in the delivery system of drugs to the targeted area.
  6. Phospholipids aid in the transportation of a drug all over the Organism body to the zone that it is inevitable to affect.
  7. Phospholipids are also known as High Bioavailable compounds because they are readily absorbed by the body.
  8. Valium is a medicine which utilizes Phospholipid-Based delivery system of the drug.
  9. Phospholipids are widely used in the food industry as Emulsifiers. An emulsifier is the compounds which disperse oil droplets within the water so that the oil and water cannot form separate layers.
  10. The yolk of the egg consists of Phospholipids and are utilize in Mayonnaise to retain it from separation.
  11. Phospholipids are present in high concentrations in Animal and Plant bases, like as Soybeans, Sunflowers, Cotton seeds, Corn, and evenly in Brains of the cow.

Biological Importance of Phospholipids

Phospholipid Bilayer