Search results
Results from the WOW.Com Content Network
Sulfur can be found under several oxidation states in nature, mainly −2, −1, 0, +2 (apparent), +2.5 (apparent), +4, and +6. When two sulfur atoms are present in the same polyatomic oxyanion in an asymmetrical situation, i.e, each bound to different groups as in thiosulfate, the oxidation state calculated from the known oxidation state of accompanying atoms (H = +1, and O = −2) can be an ...
In order to have sufficient redox potential, microorganisms that use sulfur as an electron donor often use oxygen or nitrate as terminal electron acceptors. [4] Members of the chemotrophic Acidithiobacillus genus are able to oxidize a vast range of reduced sulfur compounds, but are restricted to acidic environments. [ 5 ]
Anoxygenic photosynthesis is a special form of photosynthesis used by some bacteria and archaea, which differs from the better known oxygenic photosynthesis in plants in the reductant used (e.g. hydrogen sulfide instead of water) and the byproduct generated (e.g. elemental sulfur instead of molecular oxygen).
The oxidation of reduced sulfur compounds is performed exclusively by Bacteria and Archaea.All the Archaea involved in this process are aerobic and belong to the Order Sulfolobales, [19] [20] characterized by acidophiles (extremophiles that require low pHs to grow) and thermophiles (extremophiles that require high temperatures to grow).
Oxidation is the loss of electrons in a chemical reaction. [8] Most chemosynthetic bacteria form symbiotic associations with other small eukaryotes [9] The electrons that are released from hydrogen sulfide will provide the energy to sustain a proton gradient across the bacterial cytoplasmic membrane. This movement of protons will eventually ...
This dimer is called a special pair because of its fundamental role in photosynthesis. This special pair is slightly different in PSI and PSII reaction centers. In PSII, it absorbs photons with a wavelength of 680 nm, and is therefore called P680. In PSI, it absorbs photons at 700 nm and is called P700. In bacteria, the special pair is called ...
Disulfurous acid, metabisulfurous acid or pyrosulfurous acid is an oxoacid of sulfur with the formula H 2 S 2 O 5. Its structure is HO−S(=O) 2 −S(=O)−OH. The salts of disulfurous acid are called disulfites or metabisulfites. Disulfurous acid is, like sulfurous acid (H 2 SO 3), a phantom acid, which does not exist in the free state. [2]
In general outline, photosynthesis is the opposite of cellular respiration: while photosynthesis is a process of reduction of carbon dioxide to carbohydrates, cellular respiration is the oxidation of carbohydrates or other nutrients to carbon dioxide. Nutrients used in cellular respiration include carbohydrates, amino acids and fatty acids.