Conclusions
Both Gram positive and Gram negative bacteria have a cell wall with a rigid framework of murein, a molecule consisting of parallel polysaccharide chains cross-linked in a regular fashion by short peptide chains. Each cell is thus effectively surrounded by a net-like a sac which is really one molecule.
In gram positive bacteria (Bacillus Subtilis), the murein net is infilled with other components, mainly polysaccharides and proteins, to form a relatively thick rigid box. The walls of Gram negative bacteria (Argobacterium Tumefaciens) are thinner but more complex. Their murein layer is coated on the outside with a smooth, soft and lipid-rich layer. This protects them from lysome, an anti-bacteria enzyme found in tears, saliva and other body fluids and egg white. Lysosome breaks the polysaccharide backbone of murein by catalysing hydrolysis of certain sugar linkages. The wall is thus punctured and lysis of the cell occurs if the organism is in a hypotonic solution. …
