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ATP Citrate Lyase
ATP citrate synthase (also ATP citrate lyase (ACLY)) is an enzyme that in animals catalyzes an important step in fatty acid biosynthesis. By converting citrate to acetyl-CoA, the enzyme links carbohydrate metabolism, which yields citrate as an intermediate, with fatty acid biosynthesis, which consumes acetyl-CoA. In plants, ATP citrate lyase generates cytosolic acetyl-CoA precursors of thousands of specialized metabolites, including waxes, sterols, and polyketides. Function ATP citrate lyase is the primary enzyme responsible for the synthesis of cytosolic acetyl-CoA in many tissues. The enzyme is a tetramer of apparently identical subunits. In animals, the product, acetyl-CoA, is used in several important biosynthetic pathways, including lipogenesis and cholesterogenesis. It is activated by insulin. In plants, ATP citrate lyase generates acetyl-CoA for cytosolically-synthesized metabolites; Acetyl-CoA is not transported across subcellular membranes of plants. Such me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an Branched chain fatty acids, unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important diet (nutrition), dietary sources of fuel for animals and important structural components for cell (biology), cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthocyanins
Anthocyanins (), also called anthocyans, are water-soluble vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart named a chemical compound that gives flowers a blue color, Anthokyan, in his treatise "''Die Farben der Blüthen''" (English: The Colors of Flowers). Food plants rich in anthocyanins include the blueberry, raspberry, black rice, and black soybean, among many others that are red, blue, purple, or black. Some of the colors of autumn leaves are derived from anthocyanins. Anthocyanins belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway. They can occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits. Anthocyanins are derived from anthocyanidins by adding sugars. They are odorless and moderately astringent. Although approved as food and beverage colorant in the European Union, anthocyanins are not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprenoid
The terpenoids, also known as isoprenoids, are a class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene and its derivatives called terpenes, diterpenes, etc. While sometimes used interchangeably with "terpenes", terpenoids contain additional functional groups, usually containing oxygen. When combined with the hydrocarbon terpenes, terpenoids comprise about 80,000 compounds. They are the largest class of plant secondary metabolites, representing about 60% of known natural products. Many terpenoids have substantial pharmacological bioactivity and are therefore of interest to medicinal chemists. Plant terpenoids are used for their aromatic qualities and play a role in traditional herbal remedies. Terpenoids contribute to the scent of eucalyptus, the flavors of cinnamon, cloves, and ginger, the yellow color in sunflowers, and the red color in tomatoes. Well-known terpenoids include citral, menthol, camphor, salvinorin A in the plant '' S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaloid
Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large variety of organisms including bacteria, fungus, fungi, Medicinal plant, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction, or solvent extractions followed by silica-gel column chromatography. Alkaloids have a wide range of pharmacology, pharmacological activities including antimalarial medication, antimalarial (e.g. quinine), asthma, antiasthma (e.g. ephedrine), chemotherapy, anticancer (e.g. omacetaxine mepesuccinate, homoharringtonine), cholinomimetic (e.g. galantamine), vasodilation, vasodilatory (e.g. vincamine), Antiarrhythmic agent, antiarrhythmic (e.g. quinidine), analgesic (e.g. morphine), antibacterial (e.g. chelerythrine), and anti-diabetic, antihyperglycemic activities (e.g. berb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphenol
Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning (leather), tanning garments. Etymology The name derives from the Ancient Greek word (, meaning "many, much") and the word ‘phenol’ which refers to a chemical structure formed by attachment of an aromatic benzenoid (phenyl) ring to a hydroxyl (-OH) group (hence the ''-ol'' suffix). The term "polyphenol" has been in use at least since 1894. Definition Polyphenols are natural products with "one or several hydroxyl groups on aromatic rings", including four principal classes: phenolic acids, flavonoids, stilbenes, and lignans. Flavonoids can be grouped as flavones, flavonols, flavanols, flavanones, isoflavones, proanthocyanidins, and anthocyanins. Particularly abundant flavanoids in foods are catechin (tea, frui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malonic Acid
Malonic acid is a dicarboxylic acid with structure CH2(COOH)2. The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's diethyl ester. The name originates from the Greek word μᾶλον (''malon'') meaning 'apple'. History Malonic acid is a naturally occurring substance found in many fruits and vegetables. There is a suggestion that citrus fruits produced in organic farming contain higher levels of malonic acid than fruits produced in conventional agriculture. Malonic acid was first prepared in 1858 by the French chemist Victor Dessaignes via the oxidation of malic acid. Hermann Kolbe and Hugo Müller independently discovered how to synthesize malonic acid from propionic acid, and decided to publish their results back-to-back in the Chemical Society journal in 1864. This led to priority dispute with Hans Hübner and Maxwell Simpson who had independently published preliminary results on rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a Heterocyclic compound, heterocyclic ring (C, the ring containing the embedded oxygen). This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature, they can be classified into: *flavonoids or bioflavonoids *isoflavonoids, derived from 3-phenylchromone, chromen-4-one (3-phenyl-1,4-benzopyran, benzopyrone) structure *neoflavonoids, derived from 4-phenylcoumarin (4-phenyl-1,2-benzopyran, benzopyrone) structure The three flavonoid classes above are all ketone-containing compounds and as such, anthoxanthins (flavones and flavonols). This class was the first to be termed bioflavonoids. The terms flavonoid and bioflavo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suberin
Suberin is a lipophilic, complex polyester biopolymer found in plants. It is composed of long-chain fatty acids (called suberin acids) and glycerol. Suberin is interconnected with cutin and lignin and forms a protective barrier in the epidermal and peridermal cell walls of higher plants. Suberin and lignin are considered covalently linked to lipids and carbohydrates, respectively. Lignin is again covalently linked to suberin, and to a lesser extent to cutin, thus construdting a complex macromolecular matrix. Suberin is a major constituent of cork, and is named after the cork oak, '' Quercus suber''. Its main function is as a barrier to movement of water and solutes. Anatomy and physiology Suberin is highly hydrophobic and a somewhat 'rubbery' material. In roots, suberin is deposited in the radial and transverse/tangential cell walls of the endodermal cells. This structure, known as the Casparian strip or Casparian band, functions to prevent water and nutrients taken up by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutin
Cutin is one of two waxy polymers that are the main components of the plant cuticle, which covers all aerial surfaces of plants, the other being cutan. It is an insoluble substance with waterproof quality. Cutin also harbors cuticular waxes, which assist in cuticle structure. Cutan, the other major cuticle polymer, is much more readily preserved in fossil records. Cutin consists of omega hydroxy acids and their derivatives, which are interlinked via ester bonds, forming a polyester polymer of indeterminate size. There are two major monomer families of cutin, the C16 and C18 families. The C16 family consists mainly of 16-hydroxy palmitic acid and 9,16- or 10,16-dihydroxypalmitic acid. The C18 family consists mainly of 18-hydroxy oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Cuticle
A plant cuticle is a protecting film covering the outermost skin layer (epidermis) of leaves, young shoots and other aerial plant organs (aerial here meaning all plant parts not embedded in soil or other substrate) that have no '' periderm''. The film consists of lipid and hydrocarbon polymers infused with wax, and is synthesized exclusively by the epidermal cells. Kolattukudy, PE (1996) Biosynthetic pathways of cutin and waxes, and their sensitivity to environmental stresses. In: Plant Cuticles. Ed. by G. Kerstiens, BIOS Scientific publishers Ltd., Oxford, pp 83-108 Description The plant cuticle is a layer of lipid polymers impregnated with waxes that is present on the outer surfaces of the primary organs of all vascular land plants. It is also present in the sporophyte generation of hornworts, and in both sporophyte and gametophyte generations of mosses. The plant cuticle forms a coherent outer covering of the plant that can be isolated intact by treating plant tissue with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingolipid
Sphingolipids are a class of lipids containing a backbone of sphingoid bases, which are a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named after the mythological sphinx because of their enigmatic nature. These compounds play important roles in signal transduction and cell recognition. Sphingolipidoses, or disorders of sphingolipid metabolism, have particular impact on neural tissue. A sphingolipid with a terminal hydroxyl group is a ceramide. Other common groups bonded to the terminal oxygen atom include phosphocholine, yielding a sphingomyelin, and various sugar monomers or dimers, yielding cerebrosides and globosides, respectively. Cerebrosides and globosides are collectively known as glycosphingolipids. Structure The long-chain bases, sometimes simply known as sphingoid bases, are the first non-transient products of '' de novo'' sphingolipid synthesis in both yeast and mammals. These co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
