A Gram-positive cell wall has the following features:
In electron micrographs, a Gram-positive cell wall appears as a thick, dense wall with a thickness of about 20 nm – 80 nm.
The Gram-positive cell wall contains a large amount of peptidoglycan, which makes up about 40% to 80% of the dry weight of the cell wall. The peptidoglycan is present as numerous interconnecting layers. It provides the cell with structural support and protection against the elements.
Teichoic and teichuronic acids are interwoven in the Gram-positive cell wall. They play a role in preserving cell structure, antibiotic resistance, and cell division.
There is no outer membrane outside of the peptidoglycan layer. Instead, the peptidoglycan layer is covered by a layer of lipids and proteins.
A gelatinous material known as the periplasm lies between the peptidoglycan and the cytoplasmic membrane.
The cell wall stains purple when treated with Gram Stain.
The thick peptidoglycan layer is more vulnerable to attack by drugs such as penicillin and cephalosporins.