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Phytoene Desaturase (lycopene-forming)
Phytoene desaturase (lycopene-forming) (CrtI, ''four-step phytoene desaturase'') (, ''15-cis-phytoene:acceptor oxidoreductase (lycopene-forming)'') are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-''cis''-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in a poly-''cis'' pathway. Biochemistry Bacterial phytoene desaturases were shown to require FAD as a cofactor for their function. During the chemical reaction in total four additional double bonds are introduced into phytoene: : 15-''cis''-phytoene + 4 acceptor \rightleftharpoons all-''trans''-lycopene + 4 reduced acceptor (overall reaction) : (1a) 15-''cis''-phytoene + acceptor \rightleftharpoons all-''trans''-phytofluene + reduced acceptor : (1b) all-''trans''-phytofluene + acceptor \rightleftharpoons all-''trans''-' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoene Desaturase (zeta-carotene-forming)
Phytoene desaturase (zeta-carotene-forming) (, ''CrtIa'', ''2-step phytoene desaturase (ambiguous)'', ''two-step phytoene desaturase (ambiguous)'') is an enzyme with systematic name ''15-cis-phytoene:acceptor oxidoreductase (zeta-carotene-forming)''. This enzyme catalyses the following chemical reaction : 15-cis-phytoene + 2 acceptor \rightleftharpoons all-trans-zeta-carotene + 2 reduced acceptor (overall reaction) : (1a) 15-cis-phytoene + acceptor \rightleftharpoons all-trans-phytofluene + reduced acceptor : (1b) all-trans-phytofluene + acceptor \rightleftharpoons all-trans-zeta-carotene + reduced acceptor The enzyme is involved in carotenoid biosynthesis. See also * Phytoene desaturase (lycopene-forming) * Phytoene desaturase (neurosporene-forming) * 15-Cis-phytoene desaturase 15-''cis''-phytoene desaturases (''PDS'', ''plant-type phytoene desaturases'') (, ''15-cis-phytoene:plastoquinone oxidoreductase''), are enzymes involved in the carotenoid biosynthesis in plants and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoene Desaturase (neurosporene-forming)
Phytoene desaturase (neurosporene-forming) (, ''3-step phytoene desaturase'', ''three-step phytoene desaturase'', ''phytoene desaturase (ambiguous)'', ''CrtI (ambiguous)'') is an enzyme with systematic name ''15-cis-phytoene:acceptor oxidoreductase (neurosporene-forming)''. This enzyme catalyses the following chemical reaction : 15-''cis''-phytoene + 3 acceptor \rightleftharpoons all-''trans''-neurosporene + 3 reduced acceptor (overall reaction) : (1a) 15-''cis''-phytoene + acceptor \rightleftharpoons all-''trans''-phytofluene + reduced acceptor : (1b) all-''trans''-phytofluene + acceptor \rightleftharpoons all-''trans''-''zeta''-carotene + reduced acceptor : (1c) all-''trans''-''zeta''-carotene + acceptor \rightleftharpoons all-''trans''-neurosporene + reduced acceptor This enzyme is involved in carotenoid biosynthesis. See also * Phytoene desaturase (lycopene-forming) * 15-Cis-phytoene desaturase * Phytoene desaturase (zeta-carotene-forming) Phytoene desaturase (zeta-ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Rice
Golden rice is a variety of rice (''Oryza sativa'') produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A, in the edible parts of the rice. It is intended to produce a fortified food to be grown and consumed in areas with a shortage of dietary vitamin A. Vitamin A deficiency causes xerophthalmia, a range of eye conditions from night blindness to more severe clinical outcomes such as keratomalacia and corneal scars, and permanent blindness. It also increases risk of mortality from measles and diarrhea in children. In 2013, the prevalence of deficiency was the highest in sub-Saharan Africa (48%; 25–75), and South Asia (44%; 13–79). Although golden rice has met significant opposition from environmental and anti-globalisation activists, more than 100 Nobel laureates in 2016 encouraged use of genetically modified golden rice which can produce up to 23 times as much beta-carotene as the original golden rice. History Research for develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-carotene
β-Carotene is an organic, strongly coloured red-orange pigment abundant in fungi, plants, and fruits. It is a member of the carotenes, which are terpenoids (isoprenoids), synthesized biochemically from eight isoprene units and thus having 40 carbons. Among the carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate. In some Mucoralean fungi, β-Carotene is a precursor to the synthesis of trisporic acid. β-Carotene is the most common form of carotene in plants. When used as a food coloring, it has the E number E160a. The structure was deduced by Karrer et al. in 1930. In nature, β-carotene is a precursor (inactive form) to vitamin A via the action of beta-carotene 15,15'-monooxygenase. Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography. It can also be extracted from the beta-carotene rich algae, ''Dunaliella salina''. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima ''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown in West Africa around 3,000 years ago. In agriculture, it has largely been replaced by higher-yielding Asian r ...'' (African rice). The name wild rice is usually used for species of the genera ''Zizania (genus), Zizania'' and ''Porteresia'', both wild and domesticated, although the term may also be used for primitive or uncultivated varieties of ''Oryza''. As a cereal, cereal grain, domesticated rice is the most widely consumed staple food for over half of the world's World population, human population,Abstract, "Rice feeds more than half the world's population." especially in Asia and Africa. It is the agricultural commodity with the third-highest worldwide production, after sugarcane and maize. Since sizable portions of sugarcane and ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetically Modified Tomato
A genetically modified tomato, or transgenic tomato, is a tomato that has had its genes modified, using genetic engineering. The first trial genetically modified food was a tomato engineered to have a longer shelf life (the Flavr Savr), which was on the market briefly beginning on May 21, 1994. The first direct consumption tomato was approved in Japan in 2021. Primary work is focused on developing tomatoes with new traits like increased resistance to pests or environmental stresses. Other projects aim to enrich tomatoes with substances that may offer health benefits or be more nutritious. As well as aiming to produce novel crops, scientists produce genetically modified tomatoes to understand the function of genes naturally present in tomatoes. Wild tomatoes are small, green and largely unappetizing, but after centuries of breeding there are now thousands of varieties grown worldwide. Agrobacterium-mediated genetic engineering techniques were developed in the late 1980s that coul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurosporene
Neurosporene is a carotenoid pigment. It is an intermediate in the biosynthesis of lycopene Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene (from the neo-Latin ''Lycopersicum'', the tomato species) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables. Occu ... and a variety of bacterial carotenoids. References Carotenoids {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytofluene
Phytofluene is a colorless carotenoid found naturally in tomatoes and other vegetables. It is the second product of carotenoid biosynthesis. It is formed from phytoene in a desaturation reaction leading to the formation of five conjugated double bonds. In the following step, addition of carbon-carbon conjugated double bonds leads to the formation of z-carotene and appearance of visible color. Phytofluene has an absorption spectra in the UVA range, with maximal absorption at 348 nm and with ε1% of 1557. Analysis of several fruits and vegetables showed that phytoene and phytofluene are found in majority of fruits and vegetables. In contrast to all other carotenoids, phytoene Phytoene () is a 40-carbon intermediate in the biosynthesis of carotenoids. The synthesis of phytoene is the first committed step in the synthesis of carotenoids in plants. Phytoene is produced from two molecules of geranylgeranyl pyrophosphate (G ... and phytofluene, the first carotenoid precursors i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
