Kingdom Monera - Cell Wall
Description:
Cell wall it is a rigid solid covering which provides shape and structure to the cell. Some of the characteristics of cell wall are −
- Cell wall is present in between plasma membrane and glycocalyx.
- Periplasmic space occurs between plasma membrane and cell wall.
- In gram positive bacteria this cell wall is single layered and smooth.
- In gram negative bacteria cell wall is thick, wavy, complex and two layered. The outer layer is called outer membrane.
Components of cell wall
The outer membrane consists of channel proteins called porins.
Single layered cell wall of gram positive bacteria and the inner layer of gram negative is made up of peptidoglycan, proteins, carbohydrates, lipids, amino acids etc.
Peptidoglycan also known as murein or mucopeptide makes the cell wall.
Peptidoglycan is formed of repeating units of N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM).
In gram positive bacteria the wall contains teichoic acids that form receptor sites and surface antigens.
In some bacteria such as Mycobacteria the wall contains long chain fatty acids called mycolic acids.