Bacterial cell wall (peptidoglycan) and cell membrane

The **bacterial cell wall** is a vital, mesh-like structure primarily composed of **peptidoglycan**, which protects bacterial cells from osmotic lysis, maintains cell shape, and provides structural integrity[1][2][4]. The **cell wall** is synthesized from cytoplasmic precursors (notably, the lipid-linked disaccharide-pentapeptide "lipid II") that are flipped across the **cytoplasmic (plasma) membrane** by specialized transporters (e.g., MurJ), where they are polymerized and cross-linked by penicillin-binding proteins and other enzymes[1][3][7]. The **bacterial cell membrane** is a phospholipid bilayer that encapsulates the cytoplasm and mediates crucial processes including energy generation, nutrient uptake, and transport of wall precursors[5][6]. Both the cell wall and membrane are canonical targets for antibacterial agents—many antibiotics block cell wall synthesis, while others disrupt the cell membrane, leading to bacterial death or lysis[2][4][5]. These structures are not unique to a single molecular target but represent essential, druggable features of bacteria that are absent or fundamentally different from those of human cells, enabling selective toxicity[2][4][5].

Other names

Bacterial cell envelopeCell envelopePeptidoglycan layer (for the wall)Cytoplasmic membranePlasma membrane

Inhibition of peptidoglycan synthesis (via transpeptidase or glycosyltransferase inhibition) Disruption of cell wall precursor trafficking (e.g., MurJ inhibition) Permeabilization or disruption of the cell membrane integrity