Reaction Process: BioCyc:MOB3B_CYSTSYN-PWY

Hydrogen sulfide

H2S (33.9877212)

Hydrogen sulfide, also known as h2s or acide sulfhydrique, is a member of the class of compounds known as other non-metal sulfides. Other non-metal sulfides are inorganic compounds containing a sulfur atom of an oxidation state of -2, in which the heaviest atom bonded to the oxygen belongs to the class of other non-metals. Hydrogen sulfide can be found in a number of food items such as small-leaf linden, agar, devilfish, and nutmeg, which makes hydrogen sulfide a potential biomarker for the consumption of these food products. Hydrogen sulfide can be found primarily in blood and feces, as well as throughout most human tissues. Hydrogen sulfide exists in all living species, ranging from bacteria to humans. In humans, hydrogen sulfide is involved in a couple of metabolic pathways, which include cysteine metabolism and cystinosis, ocular nonnephropathic. Hydrogen sulfide is also involved in beta-mercaptolactate-cysteine disulfiduria, which is a metabolic disorder. Moreover, hydrogen sulfide is found to be associated with hydrogen sulfide poisoning. Hydrogen sulfide is a non-carcinogenic (not listed by IARC) potentially toxic compound. Hydrogen sulfide often results from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion. H 2S also occurs in volcanic gases, natural gas, and in some sources of well water. The human body produces small amounts of H 2S and uses it as a signaling molecule . Treatment involves immediate inhalation of amyl nitrite, injections of sodium nitrite, inhalation of pure oxygen, administration of bronchodilators to overcome eventual bronchospasm, and in some cases hyperbaric oxygen therapy (HBO). HBO therapy has anecdotal support and remains controversial (L1139) (T3DB). Hydrogen sulfide is a highly toxic and flammable gas. Because it is heavier than air it tends to accumulate at the bottom of poorly ventilated spaces. Although very pungent at first, it quickly deadens the sense of smell, so potential victims may be unaware of its presence until it is too late. H2S arises from virtually anywhere where elemental sulfur comes into contact with organic material, especially at high temperatures. Hydrogen sulfide is a covalent hydride chemically related to water (H2O) since oxygen and sulfur occur in the same periodic table group. It often results when bacteria break down organic matter in the absence of oxygen, such as in swamps, and sewers (alongside the process of anaerobic digestion). It also occurs in volcanic gases, natural gas and some well waters. It is also important to note that Hydrogen sulfide is a central participant in the sulfur cycle, the biogeochemical cycle of sulfur on Earth. As mentioned above, sulfur-reducing and sulfate-reducing bacteria derive energy from oxidizing hydrogen or organic molecules in the absence of oxygen by reducing sulfur or sulfate to hydrogen sulfide. Other bacteria liberate hydrogen sulfide from sulfur-containing amino acids. Several groups of bacteria can use hydrogen sulfide as fuel, oxidizing it to elemental sulfur or to sulfate by using oxygen or nitrate as oxidant. The purple sulfur bacteria and the green sulfur bacteria use hydrogen sulfide as electron donor in photosynthesis, thereby producing elemental sulfur. (In fact, this mode of photosynthesis is older than the mode of cyanobacteria, algae and plants which uses water as electron donor and liberates oxygen). Hydrogen sulfide can be found in Alcaligenes, Chromobacteriumn, Klebsiella, Proteus and Pseudomonas (PMID: 13061742). D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D004785 - Environmental Pollutants > D000393 - Air Pollutants

Hydrogen Ion

H+ (1.0078246)

Hydrogen ion, also known as proton or h+, is a member of the class of compounds known as other non-metal hydrides. Other non-metal hydrides are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of other non-metals. Hydrogen ion can be found in a number of food items such as lowbush blueberry, groundcherry, parsley, and tarragon, which makes hydrogen ion a potential biomarker for the consumption of these food products. Hydrogen ion exists in all living organisms, ranging from bacteria to humans. In humans, hydrogen ion is involved in several metabolic pathways, some of which include cardiolipin biosynthesis cl(i-13:0/a-25:0/a-21:0/i-15:0), cardiolipin biosynthesis cl(a-13:0/a-17:0/i-13:0/a-25:0), cardiolipin biosynthesis cl(i-12:0/i-13:0/a-17:0/a-15:0), and cardiolipin biosynthesis CL(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z)/18:1(11Z)/22:5(7Z,10Z,13Z,16Z,19Z)). Hydrogen ion is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis TG(20:3(8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)/22:5(7Z,10Z,13Z,16Z,19Z)), de novo triacylglycerol biosynthesis TG(18:2(9Z,12Z)/20:0/20:4(5Z,8Z,11Z,14Z)), de novo triacylglycerol biosynthesis TG(18:4(6Z,9Z,12Z,15Z)/18:3(9Z,12Z,15Z)/18:4(6Z,9Z,12Z,15Z)), and de novo triacylglycerol biosynthesis TG(24:0/20:5(5Z,8Z,11Z,14Z,17Z)/24:0). A hydrogen ion is created when a hydrogen atom loses or gains an electron. A positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space. Due to its extremely high charge density of approximately 2×1010 times that of a sodium ion, the bare hydrogen ion cannot exist freely in solution as it readily hydrates, i.e., bonds quickly. The hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions . Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions. Under aqueous conditions found in biochemistry, hydrogen ions exist as the hydrated form hydronium, H3O+, but these are often still referred to as hydrogen ions or even protons by biochemists. [Wikipedia])

Acetate

C2H3O2- (59.0133038)

A monocarboxylic acid anion resulting from the removal of a proton from the carboxy group of acetic acid. Acetate, also known as acetic acid or ethanoate, is a member of the class of compounds known as carboxylic acids. Carboxylic acids are compounds containing a carboxylic acid group with the formula -C(=O)OH. Acetate is soluble (in water) and a weakly acidic compound (based on its pKa). Acetate can be found in a number of food items such as pitanga, soursop, green bean, and beech nut, which makes acetate a potential biomarker for the consumption of these food products. Acetate is a non-carcinogenic (not listed by IARC) potentially toxic compound. An acetate is a salt formed by the combination of acetic acid with an alkaline, earthy, or metallic base. "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula C2H3O2−. The neutral molecules formed by the combination of the acetate ion and a positive ion (called a cation) are also commonly called "acetates" (hence, acetate of lead, acetate of aluminum, etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion CH3CO2−, or CH3COO− . In cases of skin or eye exposure, the area should be flushed with water and burns covered with dry, sterile dressings after decontamination. If ingested, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution. Watch for signs of respiratory insufficiency and assist respiration if necessary (A569) (T3DB).

D,L-Cysteine

C3H7NO2S (121.0197482)