Table 1 A summary of some of the key hallmarks that distinguish archaeal, bacterial and eukaryotic cells. Further details are presented in the text
Property | Archaea | Bacteria | Eukarya |
|---|---|---|---|
Typical Size (diameter) | 0.5-4 μm | 0.5-4 μm | 1.0-100 μm |
Chromosome(s) and mRNA | Circular, compact, with polycistronic operons. | Circular, compact, with polycistronic operons. | Linear chromosomes, genes with introns, long intergenic sequences. Monocistronic transcripts, complex spliceosome, mRNA poly A tail. Nucleolus. |
Internal structure | No membrane-enveloped organelles. No nucleus. | No membrane-enveloped organelles. No nucleus. | Membrane-enveloped organelles, mitochondria and nucleus. |
Cytoarchitecture | simple | simple | complex |
ATP-generation | Chemiosmosis across the cell membrane | Chemiosmosis across the cell membrane | Chemiosmosis across the mitochondrial membrane. |
Membrane lipids | • Glycerol-ether lipids. • sn-glycerol-1-phosphate backbone. • Isoprenoid side chains. | • Glycerol-ester lipids. • sn-glycerol-3-phosphate backbone. • Fatty acid side chains. | • Glycerol-ester lipids. • sn-glycerol-3-phosphate backbone. • Fatty acid side chains. |