Structure Pili + / - No Flagellum + / - No Proteins Capsule + / - LPS Yes R-core: (-) sugars stabilized by (+) Mg and Ca ions from environment O-polysac replaced in capsules - Phospholipids - Gram Req . No Polypeptides or Periplasm + / - Peptidoglycan + / - Cytoplasmic Membrane + / - Cytoplasm + / - Yes Yes Yes Phospholipid bilayer Yes Composition Protein subunits: pilins Anchored in cytoplasmic membrane or cell wall polysaccharides O-polysac: uncharged sugars (dif. for each B) Lipid A layer touches phospholipids Lipid A: hydrocarbon tails Yes Concentrated gel-like matrix + = contains LTA - = contains lipoproteins Glycan chains: two sugars (NAG, NAM) Lysozymes break down NAM, NAG + = teichoic acids anchored X linking peptides: + = LTA anchored Pili, flagellum anchored Ribosomes, proteins, mRNA, tRNA, ions, mol Relation to Other Structures Anchored in cytoplasmic membrane Outermost layer - = polysac part of capsule replaces O-polysac of LPS + = linked to NAM and NAG of PG NAM, NAG linked to capsules (opt.) Function Attachment to surfaces Twitching motility Transfer of DNA Locomotion: swimming Attachment to surfaces During attachment, nutrients concentrate at solid-liquid interfaces -> prevents starvation Resistance to predation via phagocytosis
Nucleoid + / - Yes Chromosome (DNA + proteins)