Question

What are phospholipids ? Briefly discuss their structure, properties and functions.

Answer 1

Phospholipids are the class of lipids that are a major component of all cell membranes. Phospholipids consist of a hydrophilic (or 'water loving') head and a hydrophobic (or 'water fearing') tail.

This is the structure of the phospholipid. Phospholipids are made up of two fatty acids which are attached to a glycerol 'head' with the phosphate group.

Properties of phospholipid:

1. They can form lipid bilayers because of their amphiphilic characteristic.
   
2. Cells and organelles are surrounded by water and they contain a watery cytoplasm, which causes the phospholipids to spontaneously arrange themselves in a double layer that is very stable.
   
3. Outside the cell, the hydrophilic heads face the water and their hydrophobic tails are directed inward. Inside the cell, the hydrophilic heads face the cytoplasm and their hydrophobic tails are directed outward.
   

Functions of phospholipid:

Phospholipids form the membrane that makes up the outer layer of all human cells. They play a key role in determining what enters and exits every cell. These cells contain molecules that simultaneously attract and resist water, they are considered amphipathic.