LPS surface proteins teichoic acid o polysaccharid lipid A lipoteichoic acid membrane peptidoglycan 国Q国○国Q国Q NAM NAG peptidoglycan 国O国Oo国O国 mmmmmmmmm cytoplasmic cytoplasmic membrane membrane phospholipid phospholipid Structure of a Gram-Negative Cell Wall Structure of a Gram-Positive Cell WallStructure of a Gram-Negative Cell Wall Structure of a Gram-Positive Cell Wall