Differences between archaea and bacteria

Both bacteria and archaea have different Ribosomal RNAs (rRNA). Archea have three RNA polymerases like eukaryotes, but bacteria have only one. Archaea have cell walls that lack peptidoglycan and have membranes that enclose lipids with hydrocarbons rather than fatty acids (not a bilayer). These lipids in the membranes of archaea are unique and contain ether linkages between the glycerol backbones rather than ester linkages. Archaea resembles eukaryotes more than bacteria. Their ribosomes work more like eukaryotic ribosomes than bacterial ribosomes.

These two microorganisms also differ in genetic and biochemical ways. Only within the last couple of decades, archaea were recognized as a distinct domain of life. They are extremophiles, meaning they thrive in physically or geochemically extreme conditions. They have similar ecological roles as bacteria. Both of these organisms react to various antibiotics in a different way.