plasma membrane GO:0005886 GO:0005904 NIF_Subcellular:sao1663586795 The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins. Wikipedia:Cell_membrane bacterial inner membrane cell membrane cellular membrane cellular_component cytoplasmic membrane go.owl inner endospore membrane juxtamembrane plasma membrane lipid bilayer plasmalemma pro.owl membrane cell part