How are the membrane lipids of archaea different from those of bacteria and eukaryotes?

The membrane lipids of archaea are chemically distinct from those found in bacteria and eukaryotes.

While bacteria and eukaryotes produce membrane lipids consisting of fatty acids linked to a molecule of glycerol by ester bonds, archaea utilize ether bonds to connect their lipids to glycerol molecules. Furthermore, the lipid components in archaea are composed of branched isoprenoids, whereas bacteria and eukaryotes typically rely on fatty acids.12

These structural differences are fundamental to the classification of archaea as a distinct domain of life, separate from the other two domains. While a very small number of bacteria have been found to contain ether-linked lipids, there are no known instances of archaea possessing ester-linked lipids.1