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Temporal Gland
Temporins are a family of peptides isolated originally from the skin secretion of the European red frog, ''Rana temporaria''. Peptides belonging to the temporin family have been isolated also from closely related North American frogs, such as ''Rana sphenocephala''. In elephants, temporin is secreted by temporal glands during the period of musth. It contains proteins, lipids (notably cholesterol), phenols, cresols and sesquiterpenes (notably farnesol Farnesol is a natural 15-carbon organic compound which is an acyclic sesquiterpene alcohol. Under standard conditions, it is a colorless liquid. It is hydrophobic, and thus insoluble in water, but miscible with oils. Farnesol is produced from 5- ... and its derivatives). This is not related to temporins that are antimicrobial peptides. In old Sanskrit texts, it is referred to as rut fluid (, or ) and is considered to be a symbol of potency and vigour:Bana, ''Kadambari''. Transl. P. Rajappa, Penguin Books 2010, p. 19 However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid. Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as '' Mycoplasma'', which require cholesterol for growth. François Poulletier de la Salle first identified cholesterol in solid form in gallstones in 1769. However, it was not until 1815 that chemist Michel Eugène Chevreul named the compound "cholesterine". Etymology The word "cholesterol" comes from the Ancient Greek ''chole- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Rut (mammalian Reproduction)
The rut (from the Latin ''rugire'', meaning "to roar") is the mating season of certain mammals, which includes ruminants such as deer, sheep, camels, goats, pronghorns, bison, giraffes and antelopes, and extends to others such as skunks and elephants. The rut is characterized in males by an increase in testosterone, exaggerated sexual dimorphisms, increased aggression, and increased interest in females. The males of the species may mark themselves with mud, undergo physiological changes or perform characteristic displays in order to make themselves more visually appealing to the females. Males also use olfaction to entice females to mate using secretions from glands and soaking in their own urine. During the rut (known as the ''rutting period'' and in domestic sheep management as '' tupping''), males often rub their antlers or horns on trees or shrubs, fight with each other, wallow in mud or dust, self-anoint and herd estrus females together. These displays make the male cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Oxford University Press
Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books by decree in 1586, it is the second oldest university press after Cambridge University Press. It is a department of the University of Oxford and is governed by a group of 15 academics known as the Delegates of the Press, who are appointed by the vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, opposite Somerville College, in the inner suburb of Jericho. For the last 500 years, OUP has primarily focused on the publication of pedagogical texts a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Farnesol
Farnesol is a natural 15-carbon organic compound which is an acyclic sesquiterpene alcohol. Under standard conditions, it is a colorless liquid. It is hydrophobic, and thus insoluble in water, but miscible with oils. Farnesol is produced from 5-carbon isoprene compounds in both plants and animals. Phosphate-activated derivatives of farnesol are the building blocks of possibly all acyclic sesquiterpenoids. These compounds are doubled to form 30-carbon squalene, which is the precursor for steroids in plants, animals, and fungi. Farnesol and its derivatives are important starting compounds for natural and artificial organic synthesis. Uses Farnesol is present in many essential oils such as citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam, and tolu. It is used in perfumery to emphasize the odors of sweet, floral perfumes. It enhances perfume scent by acting as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac perf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. Sesquiterpenes are found naturally in plants and insects, as semiochemicals, e.g. defensive agents or pheromones. Biosynthesis and examples The reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15-carbon farnesyl pyrophosphate (FPP), which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Cresol
Cresols (also hydroxytoluene or cresylic acid) are a group of aromatic organic compounds. They are widely-occurring phenols (sometimes called ''phenolics'') which may be either natural or manufactured. They are also categorized as methylphenols. Cresols commonly occur as either solids or liquids because their melting points are generally close to room temperature. Like other types of phenols, they are slowly oxidized by exposure to air, and the resulting impurities often give the samples a yellow to brownish red tint. Cresols have an odor characteristic to that of other simple phenols, reminiscent to some of a "coal tar" smell. The name "cresol" is an adduct of phenol and their traditional source, creosote. Structure and production In its chemical structure, a molecule of cresol has a methyl group substituted onto the ring of phenol. There are three forms (isomers) of cresol: ''ortho''-cresol ( ''o''-cresol), ''meta''-cresol ( ''m''-cresol), and ''para''-cresol ( ''p''-cresol). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/ unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid resid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Musth
Musth or must (from Persian, )''The Oxford Dictionary and Thesaurus: American edition'', published 1996 by Oxford University Press; p. 984 is a periodic condition in bull (male) elephants characterized by aggressive behavior and accompanied by a large rise in reproductive hormones. Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth or merely a contributing factor is unknown. Scientific investigation of musth is problematic because even the most placid elephants become violent toward humans and other elephants during musth. Musth differs from rut in that the female elephant's estrus cycle is not seasonally linked, whereas musth most often takes place in winter. Furthermore, bulls in musth have often been known to attack female elephants, regardless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |