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Alginic Acid
Alginic acid, also called algin, is a naturally occurring, edible polysaccharide found in brown algae. It is hydrophilic and forms a viscous gum when hydrated. When the alginic acid binds with sodium and calcium ions, the resulting salts are known as alginates. Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular, or powdered forms. It is a significant component of the biofilms produced by the bacterium ''Pseudomonas aeruginosa'', a major pathogen found in the lungs of some people who have cystic fibrosis. The biofilm and ''P. aeruginosa'' have a high resistance to antibiotics, but are susceptible to inhibition by macrophages. Alginate was discovered by British chemical scientist E. C. C. Stanford in 1881, and he patented an extraction process for it in the same year. The alginate was extracted, in the original patent, by first soaking the algae in water or diluted acid, then extracting the alginate by soaking it in sodium carbonate, and finall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covalently
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full valence shell, corresponding to a stable electronic configuration. In organic chemistry, covalent bonding is much more common than ionic bonding. Covalent bonding also includes many kinds of interactions, including σ-bonding, π-bonding, metal-to-metal bonding, agostic interactions, bent bonds, three-center two-electron bonds and three-center four-electron bonds. The term "covalence" was introduced by Irving Langmuir in 1919, with Nevil Sidgwick using "co-valent link" in the 1920s. Merriam-Webster dates the specific phrase ''covalent bond'' to 1939, recognizing its first known us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demonstrate both monophyly and validity as a separate lineag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminaria
''Laminaria'' is a genus of brown algae, brown seaweed in the order Kelp, Laminariales (kelp), comprising 31 species native to the north Atlantic and northern Pacific Oceans. This economically important genus is characterized by long, leathery Lamina (algae), laminae and relatively large size. Some species are called Devil's apron, due to their shape, or sea colander, due to the perforations present on the Lamina (algae), lamina. Others are referred to as ''tangle''. ''Laminaria'' form a habitat for many fish and invertebrates. The life cycle of ''Laminaria'' has wikt:heteromorphic, heteromorphic alternation of generations which differs from ''Fucus''. At meiosis the male and female zoospores are produced separately, then germinate into male and female gametophytes. The female egg matures in the oogonium until the male sperm fertilizes it. Life-Cycle: The most apparent form of ''Laminaria'' is its sporophyte phase, a structure composed of the holdfast (biology), holdfast, the Sti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascophyllum Nodosum
''Ascophyllum nodosum'' is a large, common cold water seaweed or brown alga ( Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the northern Atlantic Ocean, along the north-western coast of Europe (from the White Sea to Portugal) including east Greenland and the north-eastern coast of North America. Its range further south of these latitudes is limited by warmer ocean waters. It dominates the intertidal zone. ''Ascophyllum nodosum'' has been used numerous times in scientific research and has even been found to benefit humans through consumption. Scientific name history ''Ascophyllum nodosum'' is the only species in the genus ''Ascophyllum''. The original name (basionym) was ''Fucus nodosus'' Linnaeus 1753. The species was transferred to the genus ''Ascophyllum'' (as ''Ascophylla'') by Stackhouse (Papenfuss 1950), under the name ''Ascophyllum laevigata'' (Guiry and G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laminaria Japonica
''Saccharina japonica'' is a marine species of the Phaeophyceae (brown algae) class, a type of kelp or seaweed, which is extensively cultivated on ropes between the seas of China, Japan and Korea. It has the common name sweet kelp. It is widely eaten in East Asia. A commercially important species, ''S. japonica'' is also called ''ma-konbu'' () in Japanese, ''dasima'' () in Korean and ''hǎidài'' () in Chinese. Large harvests are produced by rope cultivation which is a simple method of growing seaweeds by attaching them to floating ropes in the ocean. The species has been cultivated in China, Japan, Korea, Russia and France. It is one of the two most consumed species of kelp in China and Japan. ''Saccharina japonica'' is also used for the production of alginates, with China producing up to ten thousand tons of the product each year. ''S. japonica'' contains very high amounts of iodine. Excessive consumption (15 g/day, containing 35 mg iodine) suppresses thyroid funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrocystis Pyrifera
''Macrocystis'' is a monospecific genus of kelp (large brown algae) with all species now synonymous with ''Macrocystis pyrifera''. It is commonly known as giant kelp or bladder kelp. This genus contains the largest of all the Phaeophyceae or brown algae. ''Macrocystis'' has pneumatocysts at the base of its blades. Sporophytes are perennial and the individual may live for up to three years; stipes/fronds within a whole individual undergo senescence, where each frond may persist for approximately 100 days. The genus is found widely in subtropical, temperate, and sub-Antarctic oceans of the Southern Hemisphere and in the northeast Pacific. ''Macrocystis'' is often a major component of temperate kelp forests. Despite its appearance, it is not a plant; it is a heterokont. Giant kelp is common along the coast of the northeastern Pacific Ocean, from Baja California north to southeast Alaska, and is also found in the southern oceans near South America, South Africa, Australia, and New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelp
Kelps are large brown algae or seaweeds that make up the order (biology), order Laminariales. There are about 30 different genus, genera. Despite its appearance and use of photosynthesis in chloroplasts, kelp is technically not a plant but a stramenopile (a group containing many protists). Kelp grow from stalks close together in kelp forest, very dense areas like forests under shallow temperate and Arctic oceans. They were previously thought to have appeared in the Miocene, 5 to 23 million years ago based on fossils from California. New fossils of kelp holdfasts from early Oligocene rocks in Washington State show that kelps were present in the northeastern Pacific Ocean by at least 32 million years ago. The organisms require nutrient-rich water with temperatures between . They are known for their high growth rate—the genera ''Macrocystis'' and ''Nereocystis'' can grow as fast as half a metre a day (that is, about 20 inches a day), ultimately reaching .Thomas, D. 2002. ''Seaweed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phaeophyceae
Brown algae (: alga) are a large group of multicellular algae comprising the class Phaeophyceae. They include many seaweeds located in colder waters of the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, '' Macrocystis'', a kelp of the order Laminariales, may reach in length and forms prominent underwater kelp forests that contain a high level of biodiversity. Another example is '' Sargassum'', which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Some members of the class, such as kelps, are used by humans as food. Between 1,500 and 2,000 species of brown algae are known worldwide. Some species, such as '' Ascophyllum nodosum' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seaweeds
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen. Natural seaweed ecosystems are sometimes under threat from human activity. For example, mechanical dredging of kelp destroys the resource and dependent fisheries. Other forces also threaten some seaweed ecosystems; for example, a wasting disease in predators of purple urchins has led to an urchin population surge which has destroyed large kelp forest regions off the coast of California. Humans have a long history of cultivating seaweeds for their uses. In recent years, seaweed farming has become a global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epimer
In stereochemistry, an epimer is one of a pair of diastereomers. The two epimers have opposite configuration at only one stereogenic center out of at least two. All other stereogenic centers in the molecules are the same in each. Epimerization is the interconversion of one epimer to the other epimer. Doxorubicin and epirubicin are two epimers that are used as drugs. Examples The stereoisomers β-D- glucopyranose and β-D- mannopyranose are epimers because they differ only in the stereochemistry at the C-2 position. The hydroxy group in β-D-glucopyranose is equatorial (in the "plane" of the ring), while in β-D-mannopyranose the C-2 hydroxy group is axial (up from the "plane" of the ring). These two molecules are epimers but, because they are not mirror images of each other, are not enantiomers. (Enantiomers have the same name, but differ in D and L classification.) They are also not sugar anomers, since it is not the anomeric carbon involved in the stereochemistry. Simila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
