The structure of the cytoplasmic membrane of prokaryotes is similar to that of eukaryotes: a phospholipid bilayer. Thus, medications that damage the prokaryotic membrane would likely adversely impact mammalian membranes as well. In contrast, peptidoglycan is unique to prokaryotes, and the prokaryotic ribosome (70S) is different from that of eukaryotic cells (80S) (although it is the same as the mitochondrial ribosomes)