Describe briefly the cell wall of bacteria or prokaryotes

Cell wall is the second layer of the cell envelope below the glycocalyx. This layer gives bacteria their characteristic shape and also provides strong structural support to prevent a bacterium from bursting or collapsing in a hypotonic solution.
Peptidoglycan, also known as murein, is the single most important component of the bacterial cell wall. It is a polymer that exists as one immense, covalently linked molecule. It forms a supporting net around a bacterium that resembles multiple layers of chain-link fence.
In the peptidoglycan polymer, molecules of N-acetylglucosamine alternate with molecules of N-acetylmuramic acid. These molecules are cross-linked by short peptide chains to provide a strong but flexible support framework.