GRAM POSITIVE VS GRAM NEGATIVE BACTERIA

Bacteria have cell walls made up of polysaccharides that give them strength and rigidity. This is important since bacteria often experience variations in osmotic strength from solutions of their environment, and their cell walls prevent them from shrinking or swelling. As a reminder, osmosis is the process by which solvent molecules pass through a semipermeable membrane from a less concentrated solution to a more concentrated one, equalizing the concentration on either side of the membrane. Nearly all bacterial cell walls have a peptide-polysaccharide layer called peptidoglycan, or sometimes murein. Peptidoglycan is a polymer made up of sugars and amino acids which forms a kind of mesh. Bacteria can be classified based on their reaction to the Gram stain, which identifies them based on the chemical and physical properties of their cell walls, as gram positive or gram negative. Gram positive bacteria have a thick cell wall, which consists of up to around 30 layers of peptidoglycan. This cell wall surrounds