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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 of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. 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 between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystallography is still the prima ... [...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 List of enzymes, systematic name ''15-cis-phytoene:acceptor oxidoreductase (zeta-carotene-forming)''. This enzyme catalysis, 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 * Phytoene desaturase (3,4-didehydrolycopene-forming) References External links * {{Portal bar, Biology, border=no EC 1.3.99 ... [...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-car ... [...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. Genetically modified golden rice can produce up to 23 times as much beta-carotene as the original golden rice. Golden rice is generally considered to be safe, with the FDA, Health Canada, International Rice Research Institute and the Bill & Melinda Gates Foundation supporting its use. It has been met with significant opposition from some environmental and anti-globalisation activists, alleging risks regarding biodiversity and expressing concerns about unforeseen health effects and socioeconomic impacts. In 2016, 107 Nobel laureates wrote an open letter to Greenpeace and its supporters, asking them to abandon their campaign against genetically modified crops in general and golden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rice
Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much less commonly, ''Oryza glaberrima'' (African rice). Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2023, 800 million tons were produced, placing it third after sugarcane and maize. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by List of rice diseases, diseases such as rice blast. Traditional rice polyc ... [...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 in the USA. The first direct-consumption tomato was approved in Japan in 2021. Primary work is focused on developing tomatoes with new Phenotypic trait, traits, such as increased resistance to pests or environmental stresses. Other projects aim to enrich tomatoes with substances that may offer health benefits or be more human nutrition, nutritious. As well as aiming to produce novel crops, scientists produce genetically modified tomatoes to understand the function of genes naturally present in tomatoes. ''Agrobacterium''-mediated genetic engineering techniques were developed in the late 1980s that could successfully transfer genetic material into the Cell nucleus, nuclear genome of tomatoes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. 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 non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...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 '' Lycopersicon'', the name of a former tomato genus) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and ve ... 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 and phytofluene, the first carotenoid precursors in the biosynthetic pathway of other carotenoids absorb light in the UV range. Dietary phytoene and phytofluene are accumulated in human skin. The accumulation of these carotenoids may protect the skin by several mechanisms: acting as UV absorbers, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
