Chapter 6: Survey of Prokaryotes

Gram-positive cells

are bacteria that have a thick peptidoglycan layer in their cell wall, retaining the crystal violet stain used in Gram staining, appearing purple under a microscope.

Teichoic acids and lipoteichoic acids

are components found in the cell walls of Gram-positive bacteria, contributing to cell wall rigidity and playing a role in cell division and adherence.

Gram-negative bacteria

are bacteria that have a thinner peptidoglycan layer and an outer membrane, which do not retain the crystal violet stain in Gram staining, instead appearing pink under a microscope.

Lipopolysaccharide

each strain of gram negative bacteria has only one molecular form of lipopolysaccharide

3 segments of lipopolysaccharide

O-side chain, core oligosaccharide, lipid A

Cell wall

composed of peptidoglycan that provides structural support and protection to bacterial cells.

Cross bridge

provides structural stability