Compare and contrast archaea and bacteria, with particular attention to the features that lead to their placement in separate taxa

Question

What will be an ideal response?

Answer 1

Bacterial cell walls are composed of peptidoglycan, whereas archaeal cell walls are composed of a variety of carbohydrate forms but never peptidoglycan. The flagella of the two groups of prokaryotes have several differences, including size, manner of assembly, and function. Although both have fimbriae, archaea have a distinctive attachment structure called a hamus that is somewhat like a barbed grappling hook. Bacterial cytoplasmic membranes may contain hopanoids, archaeal cytoplasmic membranes do not. The ribosomes of archaea and bacteria are of similar size, but some ribosomal components of archaea are more like those of eukaryotic ribosomes than those of bacteria. RNA metabolism in the two prokaryotic groups differs, and the archaeal genetic code is more like that of eukaryotes than that of bacteria. Archaeal phospholipids are different from bacterial and eukaryotic phospholipids in that the glycerol is a stereoisomer, the linkages are ether instead of ester between hydrocarbon chains and glycerol, the hydrocarbon chains are isoprene chains rather than fatty acids, which are branched rather than linear, as the fatty acids are.