Injury and Repair of Gram-Negative Bacteria, with Special Consideration of the Involvement of the Cytoplasmic Membrane

Abstract

This chapter discusses the injury and repair of gram-negative bacteria, with special consideration of the involvement of the cytoplasmic membrane. The cytoplasmic membrane of Gram-negative bacteria is approximately 6 to 9 nm thick and consists predominantly of protein and lipid, as do all biological membranes. The structure of the membrane is in a two-dimensional arrangement of proteins embedded in a lipid bilayer. The major components of the cytoplasmic membrane are proteins, which have been placed in two general classes designated as peripheral and integral. Peripheral proteins are loosely bound to the membrane by electrostatic or hydrophobic interactions, whereas integral proteins are partially embedded in and partially protruding from the membrane. The function of the cytoplasmic membrane includes the maintenance of a permeability barrier, the transport of molecules and ions, and energy production. Because the cell wall is easily penetrated by most low-molecular-weight molecules, the membrane functions as the main cellular structure for controlling passive diffusion and active transport of molecules and ions in and out of the cell.