Eubacteria are true bacteria. They:

-contain peptidoglycan in cell wall

-straight-chain ester-linked lipids in cell membrane

-four subunit RNA polymerase core

-some are pathogenic

The classification archaebacteria is outdated. Archaea are separate from bacteria because they have unique characteristics. They:

-lack peptidoglycan in cell walls

-branched-chain ether-linked lipids in cell membrane

-can obtain energy through methanogenesis

-lipid stereochemistry is opposite of that in other organisms

-lack thymine in tRNA

-ten subunit RNA polymerase core

-none are pathogenic
Eubacteria and archaebacteria have similar general cell structures, but the composition and layout of those cellular components is remarkably different.