Difference Between Gram Positive and Gram Negative Cell Wall (original) (raw)

Last Updated : 23 Mar, 2023

Cell walls of gram-positive bacteria are thick and predominantly made of peptidoglycan. In the cell wall of gram-positive bacteria, long chains of sugars and amino acids make up the complex chemical known as peptidoglycan, which supports the bacterial cell wall structurally. Whereas, Gram-negative bacteria have a multilayered cell wall that is a complex construction. The outer membrane, of Gram-negative bacteria, is composed of proteins and lipopolysaccharides (LPS), which is the outermost layer.

Feature of Gram-Positive Cell Wall

• Thick peptidoglycan layer: Outside of the cytoplasmic membrane, gram-positive bacteria have a thick peptidoglycan layer. The cell's structural support and defense are provided by this peptidoglycan layer.
• Teichoic acids are polymers made of glycerol, ribitol, or glycol that are covalently attached to the peptidoglycan layer in gram-positive bacteria. Teichoic acids are involved in the preservation of cell structure, cell division, and antibiotic resistance.
• Outside of the peptidoglycan layer, Gram-positive bacteria do not possess an outer membrane, in contrast to Gram-negative bacteria. Instead, a layer of proteins and lipids covers the peptidoglycan layer.
• Susceptibility to specific antibiotics: Due to the thick peptidoglycan coating, Gram-positive bacteria are vulnerable to drugs like penicillin and cephalosporins that attack this structure.

Feature of Gram-Negative Cell Wall

Some significant aspects of the Gram-negative cell wall, which is a distinguishing trait of some species of bacteria, include:

• Thin peptidoglycan layer: In comparison to Gram-positive bacteria, gram-negative bacteria have a thinner peptidoglycan layer. The periplasmic space, which is the area between the outer and inner membranes, is where the peptidoglycan layer is found.
• Lipopolysaccharides (LPS) and proteins make up the outer membrane of gram-negative bacteria. This outer membrane serves as a defense against harmful environmental elements and hinders the entry of antimicrobial agents into the bacterial cell.
• Lipopolysaccharides (LPS): Lipid A, core polysaccharide, and O-antigen make up the LPS layer of the outer membrane. The host immune system recognizes lipid A as an endotoxin and it might result in fever, inflammation, and other infection-related symptoms.
• Porins: The outer membrane of Gram-negative bacteria contains porins, which are proteins that form channels that allow the flow of tiny molecules, such as nutrients, into the cell.

Difference Between Gram-Positive and Gram-Negative Cell Walls