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Iron sulfides occur widely in nature in the form of iron–sulfur proteins. As organic matter decays under low-oxygen (or hypoxic) conditions such as in swamps or dead zones of lakes and oceans, sulfate-reducing bacteria reduce various sulfates present in the water, producing hydrogen sulfide. Some of the hydrogen sulfide will react with metal ...
The iron sulfur proteins contain iron–sulfur clusters, some with elaborate structures, that feature iron and sulfide centers. One broad biosynthetic task is producing sulfide (S 2-), which requires various families of enzymes. Another broad task is affixing the sulfide to iron, which is achieved on scaffolds, which are nonfunctional.
The abiotic processes include the rusting of iron-bearing metals, where Fe 2+ is abiotically oxidized to Fe 3+ in the presence of oxygen, and the reduction of Fe 3+ to Fe 2+ by iron-sulfide minerals. The biological cycling of Fe 2+ is done by iron oxidizing and reducing microbes. [14] [15] Iron is an essential micronutrient for almost every ...
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]
Absorption of dietary iron in iron salt form (as in most supplements) varies somewhat according to the body's need for iron, and is usually between 10% and 20% of iron intake. Absorption of iron from animal products, and some plant products, is in the form of heme iron, and is more efficient, allowing absorption of from 15% to 35% of intake.
Three sulfide ions bridge two iron ions each, while the fourth sulfide bridges three iron ions. Their formal oxidation states may vary from [Fe 3 S 4] + (all-Fe 3+ form) to [Fe 3 S 4] 2− (all-Fe 2+ form). In a number of iron–sulfur proteins, the [Fe 4 S 4] cluster can be reversibly converted by oxidation and loss of one iron ion to a [Fe 3 ...
Iron is a mineral that is crucial for optimal health and well-being. Found naturally in many foods and dietary supplements, it is a key component of hemoglobin, the part of red blood cells ...
Plant shoots form a sink for atmospheric sulfur gases, which can directly be taken up by the foliage (dry deposition). The foliar uptake of sulfur dioxide is generally directly dependent on the degree of opening of the stomates , since the internal resistance to this gas is low.