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Vaucheria Litorea
''Vaucheria litorea'' is a species of yellow-green algae (Xanthophyceae). It grows in a filamentous fashion (forming long tubular cells connected end to end). ''V. litorea'' is a common intertidal species of coastal brackish waters and salt marshes of the Northern Atlantic, along the coasts of Europe, North America and New Zealand. It is also found in the Eastern Pacific coasts of Washington state. It is found to be able to tolerate a large range of salinities, making it euryhaline.Christensen, T. (1998). Salinity preference of twenty species of Vaucheria (Tribophyceae). Journal of the Marine Biological Association of the United Kingdom, 68, pp 531-545, doi:10.1017/S0025315400043381 Taxonomy and nomenclature The species belong to '' Vaucheria'' were initially documented within the genus ''Conferva'', at that time consisting of 21 species, when reported by Linnaeus in 1753. ''Vaucheria litorea'' have been categorized under Vaucheriaceae. Various historical classifications, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Adolph Agardh
Carl Adolph Agardh (23 January 1785 in Båstad, Sweden – 28 January 1859 in Karlstad) was a Swedish botanist specializing in algae, who was eventually appointed bishop of Karlstad. Biography In 1807 he was appointed teacher of mathematics at Lund University, in 1812 appointed professor of botany and natural sciences, and was elected a member of the Royal Swedish Academy of Sciences in 1817, and of the Swedish Academy in 1831. He was ordained a clergyman in 1816, received two parishes as prebend, and was a representative in the clerical chamber of the Swedish Parliament on several occasions from 1817. He was rector magnificus of Lund University 1819-1820 and was appointed bishop of Karlstad in 1835, where he remained until his death. He was the father of Jacob Georg Agardh, also a botanist. System of plant classification The ''Classes Plantarum'' has nine primary divisions into which his classes and natural orders are grouped. These are, with class numbers; # Acotyle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antherozoid
An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. The androecium is also the collective term for the stamens of flowering plants. Antheridia are present in the gametophyte phase of cryptogams like bryophytes and ferns. Many algae and some fungi, for example, ascomycetes and water moulds, also have antheridia during their reproductive stages. In gymnosperms and angiosperms, the male gametophytes have been reduced to pollen grains, and in most of these, the antheridia have been reduced to a single generative cell within the pollen grain. During pollination, this generative cell divides and gives rise to sperm cells. The female counterpart to the antheridium in cryptogams is the archegonium, and in flowering plants is the gynoecium. An antheridium typically consists of sterile cells and spermatogenous tissue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosystem I
Photosystem I (PSI, or plastocyanin–ferredoxin oxidoreductase) is one of two photosystems in the Light-dependent reactions, photosynthetic light reactions of algae, plants, and cyanobacteria. Photosystem I is an integral membrane protein Protein complex, complex that uses light energy to catalyze the electron transfer, transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. Ultimately, the electrons that are transferred by Photosystem I are used to produce the moderate-energy hydrogen carrier NADPH. The photon energy absorbed by Photosystem I also produces a Chemiosmosis, proton-motive force that is used to generate adenosine triphosphate, ATP. PSI is composed of more than 110 Cofactor (biochemistry), cofactors, significantly more than Photosystem II. History This photosystem is known as PSI because it was discovered before Photosystem II, although future experiments showed that Photosystem II is actually the first enzyme of the phot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Transport Chain
An electron transport chain (ETC) is a series of protein complexes and other molecules which transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this electron transfer with the transfer of protons (H+ ions) across a membrane. Many of the enzymes in the electron transport chain are embedded within the membrane. The flow of electrons through the electron transport chain is an exergonic process. The energy from the redox reactions creates an electrochemical proton gradient that drives the synthesis of adenosine triphosphate (ATP). In aerobic respiration, the flow of electrons terminates with molecular oxygen as the final electron acceptor. In anaerobic respiration, other electron acceptors are used, such as sulfate. In an electron transport chain, the redox reactions are driven by the difference in the Gibbs free energy of reactants and products. The free energy released when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diadinoxanthin
Diadinoxanthin is a pigment found in phytoplankton. It has the formula C40H54O3. It gives rise to the xanthophylls diatoxanthin and dinoxanthin. Diadinoxanthin is a plastid pigment. Plastid pigments include chlorophylls a and c, fucoxanthin, heteroxanthin, diatoxanthin, and diadinoxanthin. Diadinoxanthin is a carotenoid. It is found in diatoms, along with other carotenoids like fucoxanthin and beta-carotene. Diatoms are referred to as golden-brown microalgae because of the color of their plastids and because the carotenoids mask chlorophyll-a and chlorophyll-c. Diadinoxanthin is a xanthophyll. Xanthophyll pigments are photoprotective pigments that help protect cells from harmful effects of too much light energy (light saturation). It is present in cells along with diatoxanthin (another xanthophyll). Diadinoxanthin is stockpiled in the cell to become available when needed. Thus it is the inactive precursor of diatoxanthin, which is the active energy dissipator. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotenoid
Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, canaries, flamingos, salmon, lobster, shrimp, and daffodils. Over 1,100 identified carotenoids can be further categorized into two classes xanthophylls (which contain oxygen) and carotenes (which are purely hydrocarbons and contain no oxygen). All are derivatives of tetraterpenes, meaning that they are produced from 8 isoprene units and contain 40 carbon atoms. In general, carotenoids absorb wavelengths ranging from 400 to 550 nanometers (violet to green light). This causes the compounds to be deeply colored yellow, orange, or red. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, but many plant colors, especially reds and purples, are due to polyphenols. Carotenoids serve two key roles in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll C
Chlorophyll ''c'' refers to forms of chlorophyll found in certain marine algae, including the photosynthetic Chromista (e.g. diatoms and brown algae) and dinoflagellates. These pigments are characterized by their unusual chemical structure, with a porphyrin as opposed to the chlorin (which has a reduced ring D) as the core; they also do not have an isoprenoid tail. Both these features stand out from the other chlorophylls commonly found in algae and plants. It has a blue-green color and is an accessory pigment, particularly significant in its absorption of light in the 447–520 nm wavelength region. Like chlorophyll ''a'' and chlorophyll ''b'', it helps the organism gather light and passes a quanta of excitation energy through the light harvesting antennae to the photosynthetic reaction centre. Chlorophyll ''c'' can be further divided into chlorophyll ''c''1, chlorophyll ''c''2, and chlorophyll ''c''3, plus at least eight other more recently found subtypes. Chlorop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll A
} Chlorophyll ''a'' is a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light, and it is a poor absorber of green and near-green portions of the spectrum. Chlorophyll does not reflect light but chlorophyll-containing tissues appear green because green light is diffusively reflected by structures like cell walls. This photosynthetic pigment is essential for photosynthesis in eukaryotes, cyanobacteria and prochlorophytes because of its role as primary electron donor in the electron transport chain. Chlorophyll ''a'' also transfers resonance energy in the antenna complex, ending in the reaction center where specific chlorophylls P680 and P700 are located. Distribution of chlorophyll ''a'' Chlorophyll ''a'' is essential for most photosynthetic organisms to release chemical energy but is not the only pigment that can be used for photosynthesis. All oxygenic photosynthetic organisms use chloroph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthetic
Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism. ''Photosynthesis'' usually refers to oxygenic photosynthesis, a process that produces oxygen. Photosynthetic organisms store the chemical energy so produced within intracellular organic compounds (compounds containing carbon) like sugars, glycogen, cellulose and starches. To use this stored chemical energy, an organism's cells metabolize the organic compounds through cellular respiration. Photosynthesis plays a critical role in producing and maintaining the atmospheric oxygen, oxygen content of the Earth's atmosphere, and it supplies most of the biological energy necessary for complex life on Earth. Some bacteria also perform anoxygenic photosynthesis, which uses bacteriochlorophyll to split hydrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrenoid
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''Annu. Rev. Plant Biol.'', 56, 99-131. and in a single group of land plants, the hornworts.Villarreal, J. C., & Renner, S. S. (2012) Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years. ''Proceedings of the National Academy of Sciences'',109(46), 1873-1887. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2-rich environment around the photosynthesis, photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastid
A plastid is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. Plastids are considered to be intracellular endosymbiotic cyanobacteria. Examples of plastids include chloroplasts (used for photosynthesis); chromoplasts (used for synthesis and storage of pigments); leucoplasts (non-pigmented plastids, some of which can cellular differentiation, differentiate); and apicoplasts (non-photosynthetic plastids of apicomplexa derived from secondary endosymbiosis). A permanent primary endosymbiosis event occurred about 1.5 billion years ago in the Archaeplastida cladeEmbryophyte, land plants, red algae, green algae and glaucophytesprobably with a cyanobiont, a symbiotic cyanobacteria related to the genus ''Gloeomargarita lithophora, Gloeomargarita''. Another primary endosymbiosis event occurred later, between 140 and 90 million years ago, in the photosynthetic plastids ''Paulinella'' amoeboids of the cyanobacteria genera '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
