Title: Archaea: Definition, Characteristics & Examples - Video & Lesson Transcript | Study.com
Headings: Archaea: Definition, Characteristics & Examples
Archaea: Definition, Characteristics & Examples
Lesson Transcript
The Tree of Life
Definition of Archaea
Hyperthermophiles
Extreme Halophiles
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Archaea: Definition, Characteristics & Examples
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Content: As is the case in science, this could change at any time. But it seems that Archaea did not evolve to cause disease in mammals. Thermoacidophiles
There are also Archaea that are thermoacidophiles. These organisms grow best at high temperatures and extremely low pH. For many Archaea, this means a pH less than 2, the same pH as stomach acid. One genus of Archaea, called Picrophilus, can even survive pH values below zero. Many geothermal hot springs have very low pH due to the high sulfuric acid content. Even the combination of harsh environmental conditions like heat and acid can't seem to stop the Archaea from growing happily. Diverse Metabolism
All Archaea are chemotrophic, meaning they use chemicals to obtain energy. Some use organic compounds, like sugars, while others use inorganic compounds, like iron. One of the most common inorganic energy sources used by Archaea is hydrogen gas.