• acid
  • It is bound at its C-terminal end (a lysine) by a covalent bond to the peptidoglycan layer (specifically to diaminopimelic acid molecules) and is embedded in the outer membrane by its hydrophobic head (a cysteine with lipids attached). (wikipedia.org)
  • Peptidoglycan Pimelic acid Brooks, George H. (wikipedia.org)
  • crystal
  • Gram negative bacteria have a thinner layer of peptidoglycan, encased in a layer of lipids, and they will flush pink when exposed to crystal violet. (wisegeek.com)