Unlike bacteria, archaea are able to live in extreme environments, some produce methane, their plasmid membranes are unique compared to other lifeforms and their cell walls lack peptidoglycan, which is present in bacteria cell walls. There are three main forms of archaea: thermophiles, halophiles and methanogens.
Some of the key differences between archaea and bacteria are:
- They usually live in extreme conditions. While it is possible to find bacterial extremophiles, the majority are archaea.
- While the bacteria phospholipid membrane features ester links between polar heads and fatty acid cells, the archaea phospholipid membrane has ether links.
- Bacterial cell walls contain peptidoglycan and archaea cell walls do not.
- There are differences between bacteria and archaea RNA. Bacterial RNA polymerase has 14 subunits only, whereas archaea has several sets of eight to 12 subunits.
- Bacterial tRNA forms formaldehyde, whereas archaea tRNA forms methane
There are three main forms of archaea:
- Methanogens produce large amounts of methane gas, and so they are often used in sewage plants. They are also present in cow digestive systems.
- Halophiles love salt, which means they are most frequently found in areas like the dead sea.
- Thermophiles are able to withstand extremely hot temperatures. They are present in hot springs, volcano vents and acidic soils. It is thermophile archaea that make the hot springs at Yellowstone National Park look bright.