Figure 10.

Quinones, quinone analogues and lipids. Structures from Berry (2002) and Lengeler et al. (1999). (a) Compounds common among or specific to eubacteria (with the exception of ubiquinone). (b) Compounds specific to archaebacteria. Note the difference in glycerol configuration (Koga et al. 1998). There has been a claim that archaebacteria synthesize eubacterial-type phospholipids (Pereto et al. 2004), but reading of the original literature behind that claim (Gattinger et al. 2002) reveals that the archaebacteria in question were grown on yeast extract and/or with fatty acid supplements; the methanogens contained the lipids (Gattinger et al. 2002), the inference that they synthesized them (Pereto et al. 2004) is tenuous.