Diversity of Living Things Kingdom Archaea Diversity of Living Things

Kingdom Archaea Lives in extreme environments (eg. Hot springs, near sea floor vents at temperatures near 100C) Live without oxygen Obtain energy from inorganic molecules or from light Was classified under bacteria

Classifying archaea Have different chemical composition, RNA, and genes than those of bacteria Eg: Archaea that live in high temperatures have unusual lipids that remain stable at very high temperatures Those that live in extreme cold temperatures, have high contents of other fatty substances that remain fluid and functional at cold temperatures

Methanogens (methane-producing) Live in oxygen free environments (eg. Below surface of swamps, marshes) Use carbon dioxide, nitrogen gas, or hydrogen sulfide as a source of energy and give off methane gas as a waste product

Halophiles (salt-loving) Live in extremely saline environments (eg. Salt pools) They are so well adapted to these environments, they cannot grow in weaker salt solutions

Thermoacidophiles (acid-loving) Live in extremely hot and acidic environments (hot sulfur springs, volcanoes) Grow best at temperatures above 80C

Origin of life Earths early atmosphere lacked oxygen. Evidence shows that it consisted of water vapour and probably methane and ammonia Alexander Oparin (1930s) – Hypothesis: life began in the ocean. He proposed that the sun’s energy and electrical energy from lightening initiated chemical reactions among the atmospheres gases, resulting in the formation of organic compounds

Stanley Miller and Harold Urey (1953) set up an experiment to test Oparin’s hypothesis. They simulated what was thought to be earths early atmosphere. Also, a high voltage electrical source simulating lightening Result: chemical reactions within the chamber produced several different amino acids, sugars, and other simple organic comounds in a week’s time

However scientists could not produce any entities capable of attaining all the characteristics of living cells during experiments that approximate conditions on early earth Present day archaea possess characteristics of organisms that could live in early atmospheric conditions – if they actually did is still a debate

Biotechnology and Archaea Biotechnology and industry depend on the use of Archaean enzymes for many different processes, including DNA analysis and diagnosing diseases While standard enzymes break down and stop working when they are exposed to extreme conditions, this is not the case for Archaean enzymes