A Gram-negative cell wall has the following features:

• The outer membrane is separated from the inner cytoplasmic layer by a periplasmic space called the periplasm, which has a network of peptidoglycan chains. 
• The Gram-negative bacteria has a thin peptidoglycan layer, which is present in the periplasmic space – the area between the inner and outer membranes. 
• The cell wall is enclosed by a cell envelope, which is composed of 3 layers, including a distinctive outer membrane, a thin peptidoglycan layer, and a cytoplasmic membrane. 
• The outer membrane of the cell wall is a bilayer structure composed of lipopolysaccharides, phospholipid molecules, lipoproteins, and surface proteins. It protects the cell against harmful microbial agents and damaging environmental elements. 
• The surface proteins, known as porins, form channels that allow nutrients and other tiny molecules to flow into the cell. 
• The cell wall stains pink when treated with Gram Stain.