Peptidoglycan Outside 液态镶嵌模型3000-0300 Channel Integral Phospholipid polar(hydrophobe g. tails(fatty acids) eripheral ai Polar(hydrophilic Inside Election tomiya protein heads(phosphate group and glycerol) FIGURE 4.11 Plasma membrane. (a) Electron micrograph showing the phospholipid bilayer forming the plasma membrane of the bacterium Bacillus brevis Layers of the cell wall can be seen outside the plasma membrane. (b)Drawing of membrane showing phospholipid bilayer and proteins. The outer membrane of ram-negative bacteria is also a phospholipid bilayer. (c) Space-filling models of everal molecules as they are arranged in the phospholipid bilayer液态镶嵌模型(fluid mosaic model)