part of plasma membrane integral to plasma membrane cell membrane plasmalemma plasma membrane lipid bilayer juxtamembrane Wikipedia:Cell_membrane NIF_Subcellular:sao1663586795 cellular_component cellular membrane inner endospore membrane cytoplasmic membrane The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins. GO:0005904 GO:0005887 GO:0005886 bacterial inner membrane integral component of plasma membrane membrane cell periphery