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The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. [1]
t. e. Marine biogeochemical cycles are biogeochemical cycles that occur within marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. These biogeochemical cycles are the pathways chemical substances and elements move through within the marine environment. In addition, substances and elements ...
The iron–sulfur world hypothesis is a set of proposals for the origin of life and the early evolution of life advanced in a series of articles between 1988 and 1992 by Günter Wächtershäuser, a Munich patent lawyer with a degree in chemistry, who had been encouraged and supported by philosopher Karl R. Popper to publish his ideas.
Of the 25 known isotopes of sulfur, four are stable. [1] In order of their abundance, those isotopes are 32 S (94.93%), 34 S (4.29%), 33 S (0.76%), and 36 S (0.02%). [2] The δ 34 S value refers to a measure of the ratio of the two most common stable sulfur isotopes, 34 S: 32 S, as measured in a sample against that same ratio as measured in a known reference standard.
A biogeochemical cycle, or more generally a cycle of matter, [ 1 ] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...
Alternative abiogenesis scenarios. A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come ...
Günter Wächtershäuser. Günter Wächtershäuser (born 1938 in Gießen) is a German chemist turned patent lawyer who is widely known for his work on the origin of life, and in particular his iron-sulfur world theory, a theory that life on Earth has hydrothermal origins. The hypothesis proposes that early life may have formed on the surface of ...
1894. The Frasch process is a method to extract sulfur from underground deposits by taking advantage of the low melting point of sulfur. It is the only industrial method of recovering sulfur from elemental deposits. [1] Most of the world's sulfur was obtained this way until the late 20th century, when sulfur recovered from petroleum and gas ...