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Protoporphyrinogen Oxidase
Protoporphyrinogen oxidase or protox is an enzyme that in humans is encoded by the ''PPOX'' gene. Protoporphyrinogen oxidase is responsible for the seventh step in biosynthesis of protoporphyrin IX. This porphyrin is the precursor to hemoglobin, the oxygen carrier in animals, and chlorophyll, the dye in plants. The enzyme catalyzes the dehydrogenation (removal of hydrogen atoms) of protoporphyrinogen IX (the product of the sixth step in the production of heme) to form protoporphyrin IX. One additional enzyme must modify protoporphyrin IX before it becomes heme. Inhibition of this enzyme is a strategy used in certain herbicides. Gene The PPOX gene is located on the long (q) arm of chromosome 1 at position 22, from base pair 157,949,266 to base pair 157,954,082. Function This gene encodes the penultimate enzyme of heme biosynthesis, which catalyzes the 6-electron oxidation of protoporphyrinogen IX to form protoporphyrin IX. This protein is a flavoprotein associated with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, and proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALAS1
Delta-aminolevulinate synthase 1 also known as ALAS1 is a protein that in humans is encoded by the ''ALAS1'' gene. ALAS1 is an aminolevulinic acid synthase. Delta-aminolevulinate synthase catalyzes the condensation of glycine with succinyl-CoA to form delta-aminolevulinic acid. This nuclear-encoded mitochondrial enzyme is the first and rate-limiting enzyme in the mammalian heme biosynthetic pathway. There are 2 tissue-specific isozymes: a housekeeping enzyme encoded by the ALAS1 gene and an erythroid tissue-specific enzyme encoded by ALAS2 Delta-aminolevulinate synthase 2 also known as ALAS2 is a protein that in humans is encoded by the ''ALAS2'' gene. ALAS2 is an aminolevulinic acid synthase. The product of this gene specifies an erythroid-specific mitochondrially located enzyme .... Mice lacking this gene exhibit embryonic embryonic lethality, indicating that ALAS is essential for early embryogenesis. References External links * Further reading * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acifluorfen
Acifluorfen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to acifluorfen and its salts, via metabolic disposal by glutathione ''S''-transferase. It is effective against broadleaf weeds and grasses and is used agriculturally on fields growing soybeans, peanuts, peas, and rice. History The nitrophenyl ethers are a well-known class of herbicides, the oldest member of which was nitrofen, invented by Rohm & Haas and first registered for sale in 1964. This area of chemistry became very competitive, with the Mobil Oil Corporation's filing in 1969 and grant in 1974 of a patent to the structural analog with a COOCH3 group adjacent to the nitro group of nitrofen. This product, bifenox, was launched with the brand name Mowdown in 1981. Meanwhile Rohm & Haas introduced acifluorfen (as its sodium salt with brand na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a hydroxyl group). Ethanol is a Volatility (chemistry), volatile, Combustibility and flammability, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive recreational drug, the active ingredient in alcoholic drinks. Ethanol is naturally produced by the fermentation process of Carbohydrate, sugars by yeasts or via Petrochemistry, petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the Chemical synthesis, synthesis of organic compounds, and as a Alcohol fuel, fuel source. Ethanol also can be dehydrated to make ethylene, an important chemical feedstock. As of 2006, world produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African People
The population of South Africa is about 58.8 million people of diverse origins, cultures, Languages of South Africa, languages, and Religion in South Africa, religions. The South African National Census of 2022 was the most recent census held; the next will be in 2032. In 2011, Statistics South Africa counted 2.1 million foreigners in total. Reports suggest that is an underestimation. The real figure may be as high as five million, including some three million Demographics of Zimbabwe, Zimbabweans. History Population Earlier Censuses, 1904 to 2011 1904 Census South African population figures for the 1904 Census.Smuts I: The Sanguine Years 1870–1919, W.K. Hancock, Cambridge University Press, 1962, pg 219 1960 Census Sources: ''Statesman's Yearbook, Statesman's Year-Book'' 1967–1968; ''Europa World Year Book, Europa Year Book'' 1969 1904-85 national census numbers Bantustan demographics were removed from South African census data during Apartheid and for this reas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. Only the -arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is encoded by the codons CGU, CGC, CGA, CGG, AGA, and AGG. The guanidine group in arginine is the precursor for the biosynthesis of nitric oxide. Like all amino acids, it is a white, water-soluble solid. History Arginine was first isolated in 1886 from yellow lupin seedlings by the German chemist Ernst Schulze and his assistant Ernst Steiger. He named it from the Greek ''árgyros'' (ἄργυρος) meaning "silver" due to the silver-white appearance of arginine nitrate crystals. In 1897, Schulze and Ernst Winterstein (1865–1949) determined the structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptophan
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. It is essential in humans, meaning that the body cannot synthesize it and it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3. It is encoded by the codon UGG. Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38). Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Function Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain life. Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variegate Porphyria
Variegate porphyria, also known by several other names, is an autosomal dominant porphyria that can have acute (severe but usually not long-lasting) symptoms along with symptoms that affect the skin. The disorder results from low levels of the enzyme responsible for the seventh step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood. Signs and symptoms When symptoms occur, they can include acute attacks (similar to acute intermittent porphyria) or skin damage. Acute attacks usually begin in adulthood and cause abdominal pain, vomiting, diarrhoea and constipation. During an attack, a person may also experience muscle weakness, seizures, and mental changes such as anxiety and hallucinations. These signs and symptoms are triggered by nongenetic factors such as certain drugs, dieting or fasting, certain hormones and stress. Some people with variegate porphyria have skin that is over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UROS
The Uru or Uros ( ure, Qhas Qut suñi) are an indigenous people of Bolivia. They live on an approximate and still growing 120 self-fashioned floating islands in Lake Titicaca near Puno. They form three main groups: the Uru-Chipaya, Uru-Murato, and Uru-Iruito. The Uru-Iruito still inhabit the Bolivian side of Lake Titicaca and the Desaguadero River. History According to legend, the Uru descend from a people that spoke the Puquina language. However, while most of the Uru have shifted to Aymara and Spanish, as few as two people still spoke in 2004 the nearly extinct Uru language which is actually closely related to the Chipaya language. The Uru considered themselves the owners of the lake and water. According to the legend, Uru used to say that they had black blood, because they did not feel the cold. They historically called themselves ''Lupihaques'', "sons of the Sun". Although the Uru language is nearly extinct, the Uru continue to maintain their identity and some old custom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UROD
Uroporphyrinogen III decarboxylase (uroporphyrinogen decarboxylase, or UROD) is an enzyme () that in humans is encoded by the ''UROD'' gene. Function Uroporphyrinogen III decarboxylase is a homodimeric enzyme () that catalyzes the fifth step in heme biosynthesis, which corresponds to the elimination of carboxyl groups from the four acetate side chains of uroporphyrinogen III to yield coproporphyrinogen III: :uroporphyrinogen III \rightleftharpoons coproporphyrinogen III + 4 CO2 Clinical significance Mutations and deficiency in this enzyme are known to cause familial porphyria cutanea tarda and hepatoerythropoietic porphyria. At least 65 disease-causing mutations in this gene have been discovered. Mechanism At low substrate concentrations, the reaction is believed to follow an ordered route, with the sequential removal of CO2 from the D, A, B, and C rings, whereas at higher substrate/enzyme levels a random route seems to be operative. The enzyme functions as a dimer in so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMBS (gene)
Porphobilinogen deaminase (hydroxymethylbilane synthase, or uroporphyrinogen I synthase) is an enzyme () that in humans is encoded by the HMBS gene. Porphobilinogen deaminase is involved in the third step of the heme biosynthetic pathway. It catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane while releasing four ammonia molecules: :4 porphobilinogen + H2O \rightleftharpoons hydroxymethylbilane + 4 NH3 Structure and function Functionally, porphobilinogen deaminase catalyzes the loss of ammonia from the porphobilinogen monomer (deamination) and its subsequent polymerization to a linear tetrapyrrole, which is released as hydroxymethylbilane: The structure of 40-42 kDa porphobilinogen deaminase, which is highly conserved amongst organisms, consists of three domains. Domains 1 and 2 are structurally very similar: each consisting of five beta-sheets and three alpha helices in humans. Domain 3 is positioned between the other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
