Question

Describe the structure of phospholipids. How are they arranged in the cell membrane?

Answer 1

The phospholipids are the phosphorus containing complex lipids that are derived from glycerol. The cell membrane is made up of these compounds. The plasma membrane is the lipid bilayer. It is made up of two ends: hydrophilic and hydrophobic. It helps in the transport of selective compounds inside the cell.

Complete answer:
The basic structure of the cell membrane is made up of phospholipid. A single phospholipid molecule consists of two different ends: a head and a tail. The head is known as hydrophilic end. It contains a phosphate group (phosphorus molecule and four oxygen molecules). It is attracted towards water molecules. It is the water loving end. The tail end contains two strings of hydrogen and carbon atoms called fatty acid chains. It is the hydrophobic end and does not attach to the water molecules. It is the water hating end. The cell membrane is the lipid bilayer membrane in which phospholipids are arranged in a double layer. The hydrophilic phosphate ends are arranged near the water. Both the sides of the layer have watery fluids: intercellular fluid (inside a cell), extracellular fluid (outside a cell). The arrangement of hydrophobic ends is such that it remains away from the water.

Note: The plasma membrane is the selectively permeable membrane. It only allows the movement of ions and molecules which are important for cellular functions. Lipids, proteins, and carbohydrate groups are the principle components of the plasma membrane. Phospholipids play an important role in the body. They act as intermediates in the resynthesis of triglycerides during the absorption of fat. It also facilitates the oxidation of fatty acids.