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Complex Oil Bodies
The oil bodies of liverworts, occasionally dubbed “complex” for distinction, are unique organelles exclusive to the Marchantiophyta. They are markedly different from the oil bodies found in algae and other plants in that they are membrane-bound, and are not associated with food storage. The organelles are variable and present in an estimated 90% of liverwort species, often proving taxonomically relevant. As a whole, the formation and function of the organelles are poorly understood. Complex oil bodies are recognized as sites of isoprenoid biosynthesis and essential oil accumulation, and have been implicated with anti-herbivory, desiccation tolerance, and photo-protection. Structure and content The oil bodies of liverworts are recognizable using light microscopy, and they were first officially described in 1834 by Huebener from the plant ''Mylia'' ''taylorii''. They were noted as transparent drops, with a shining, membranous texture. They are secretory organelles bound by a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plagiochila Asplenioides Oil Bodies
''Plagiochila'' is a large, common, and widespread genus of liverworts in the order Jungermanniales. It is a member of the family Plagiochilaceae within that order. There may be anywhere from 500 to 1300 species, most of them from the tropics; the exact number is still under revision. The genus also has a wide distribution in temperate and arctic areas. Species in ''Plagiochila'' * ''Plagiochila amboynensis'' * '' Plagiochila asplenioides'' * ''Plagiochila belangeriana'' * '' Plagiochila biondiana'' * ''Plagiochila blepharophora'' * '' Plagiochila capillaris'' * ''Plagiochila chinensis'' * ''Plagiochila corticola'' * ''Plagiochila crassitexta'' * ''Plagiochila delavayi'' * ''Plagiochila deltoidea'' * '' Plagiochila determii'' * ''Plagiochila euryphyllon'' * ''Plagiochila fasciculata'' * ''Plagiochila firma'' * ''Plagiochila flexuosa'' * ''Plagiochila fordiana'' * ''Plagiochila formosae'' * ''Plagiochila frondescens'' * ''Plagiochila fruticosa'' * ''Plagiochila ghatiensis'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromaticity
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturated compounds having single bonds, and other geometric or connective non-cyclic arrangements with the same set of atoms. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, but only aromatic rings have enhanced stability. The term ''aromaticity'' with this meaning is historically related to the concept of having an aroma, but is a distinct property from that meaning. Since the most common aromatic compounds are derivatives of benzene (an aromatic hydrocarbon common in petroleum and its distillates), the word ''aromatic'' occasionally refers informally to benzene derivatives, and so it was first defined. Nevertheless, many non-be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frullania
''Frullania'' is the only genus of liverworts in family Frullaniaceae. It contains the following species: A *''Frullania aculeata'' Taylor, 1846 *''Frullania acutata'' Caspary, 1887 *''Frullania acutiloba'' Gerola, 1947 *'' Frullania akiyamae'' Hattori, 1986 *'' Frullania albertii'' Stephani, 1916 *'' Frullania allanii'' Hodgson, 1949 *'' Frullania allionii'' Stephani, 1910 *'' Frullania alpina'' Stephani, 1911 *''Frullania alstonii'' Verdoorn, 1930 *''Frullania alstonii'' var. ''pfleidereri'' Hattori, 1972 *'' Frullania alternans'' Nees In G., L. & N., 1845 *''Frullania amamiensis'' Kamimura, 1968 *''Frullania ambronnii'' Stephani, 1916 *''Frullania amplicrania'' Stephani, 1910 *''Frullania ampullifera'' Jack & Stephani In Stephani, 1894 *'' Frullania anderssonii'' Ångström, 1873 *'' Frullania angulata'' Mitten, 1863 *''Frullania angulata'' F. ''Serratoides'' Vanden Berghen, 1983 *''Frullania angulata'' var. ''laciniata'' Demaret & Vanden Berghen, 1950 *'' Frullania angusti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jungermannia
''Jungermannia'' is a genus of leafy liverworts belonging to the family Jungermanniaceae. They have a worldwide distribution. Species As accepted by World Flora Online; * '' Jungermannia achroa'' * '' Jungermannia acris'' * '' Jungermannia aculeata'' * '' Jungermannia adscendens'' * '' Jungermannia aequiloba'' * '' Jungermannia affinis'' * '' Jungermannia albicans'' * '' Jungermannia algeriensis'' * '' Jungermannia alicularia'' * '' Jungermannia allenii'' * '' Jungermannia alternifolia'' * '' Jungermannia amakawana'' * '' Jungermannia amentacea'' * '' Jungermannia amoena'' * '' Jungermannia amplexicaulis'' * '' Jungermannia amplexifolia'' * '' Jungermannia anisodonta'' * '' Jungermannia antarctica'' * '' Jungermannia appressifolia'' * '' Jungermannia aquatica'' * '' Jungermannia arenaria'' * '' Jungermannia ariadne'' * '' Jungermannia ascendens'' * '' Jungermannia asplenioides'' * '' Jungermannia atro-olivacea'' * '' Jungermannia atrobrunnea'' * '' Junger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiloscyphus
''Chiloscyphus'' is a genus of liverworts belonging to the family Lophocoleaceae. The genus has cosmopolitan distribution. Species: * ''Chiloscyphus acutus'' Steph. * ''Chiloscyphus alpicola ''Chiloscyphus'' is a genus of liverworts belonging to the family Lophocoleaceae. The genus has cosmopolitan distribution. Species: * ''Chiloscyphus acutus ''Chiloscyphus'' is a genus of liverworts belonging to the family Lophocoleaceae. Th ...'' J.J.Engel References {{Taxonbar, from=Q13573605 Jungermanniales Jungermanniales genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoterpene
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen functionality or missing a methyl group, are called monoterpenoids. Monoterpenes and monoterpenoids are diverse. They have relevance to the pharmaceutical, cosmetic, agricultural, and food industries. Biosynthesis Monoterpenes are derived biosynthetically from units of isopentenyl pyrophosphate, which is formed from acetyl-CoA via the intermediacy of mevalonic acid in the HMG-CoA reductase pathway. An alternative, unrelated biosynthesis pathway of IPP is known in some bacterial groups and the plastids of plants, the so-called MEP-(2-methyl-D-erythritol-4-phosphate) pathway, which is initiated from C5 sugars. In both pathways, IPP is isomerized to DMAPP by the enzyme isopentenyl pyrophosphate isomerase. Geranyl pyrophosphate is the precurso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpene
Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primary intermediate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol. They are known to be antimicrobial and antiinflammatory. Structures As with most terpenes a huge number of potential structures exists, which may be broadly divided according to the number of rings present. Biosynthesis Diterpenes are derived from the addition of one IPP unit to FPP to form geranylgeranyl-pyrophosphate (GGPP). From GGPP, structural diversity is achieved mainly by two classes of enzymes; the diterpene synthases and cytochromes P450. Several diterpenes are produced by plants and cyanobacteria. GGPP is also the precursor for the synthesis of the phytane by the action of the enzyme geranylger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary Action
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid. Etymology Capillary comes from the Latin word capillaris, meaning "of or resembling hair." The meaning stems from the tiny, hairlike diameter of a capillary. While capilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micromanipulator
A micromanipulator is a device which is used to physically interact with a sample under a microscope, where a level of precision of movement is necessary that cannot be achieved by the unaided human hand. It may typically consist of an input joystick, a mechanism for reducing the range of movement and an output section with the means of holding a microtool to hold, inject, cut or otherwise manipulate the object as required. The mechanism for reducing the movement usually requires the movement to be free of backlash. This is achieved by the use of kinematic constraints to allow each part of the mechanism to move only in one or more chosen degrees of freedom, which achieves a high precision and repeatability of movement, usually at the expense of some absolute accuracy. Movement Movement reduction can be performed by mechanical levers, hydraulically using pistons of different diameters connected by tubing containing non-compressible fluid, electronically using stepper motors or lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 end can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marchantia Polymorpha
''Marchantia polymorpha'' is a species of large thalloid liverwort in the class Marchantiopsida. ''M. polymorpha'' is highly variable in appearance and contains several subspecies. This species is dioicous, having separate male and female plants. ''M. polymorpha'' has a wide distribution and is found worldwide.Matthews, Robin F. 1993. Marchantia polymorpha. In: Fire Effects Information System, nline U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://www.fs.fed.us/database/feis/plants/bryophyte/marpol/all.html 017, December 8 Common names include common liverwort or umbrella liverwort. Distribution ''Marchantia polymorpha'' subsp. ''ruderalis'' has a circumpolar boreo-arctic cosmopolitan distribution, found worldwide on all continents except Antarctica. Habitat ''Marchantia polymorpha'' grows on shaded moist soil and rocks in damp habitats such as the banks of streams and pools, bogs, fen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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