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Chemosynthesis
In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrogen sulfide) or ferrous ions as a source of energy, rather than sunlight, as in photosynthesis. Chemotroph, Chemoautotrophs, organisms that obtain carbon from carbon dioxide through chemosynthesis, are phylogenetically diverse. Groups that include conspicuous or biogeochemically important taxa include the sulfur-oxidizing Gammaproteobacteria, the Campylobacterota, the Aquificota, the methanogenic archaea, and the neutrophilic iron-oxidizing bacteria. Many microorganisms in dark regions of the oceans use chemosynthesis to produce biomass from single-carbon molecules. Two categories can be distinguished. In the rare sites where hydrogen molecules (H2) are available, the energy available from the reaction between CO2 and H2 (leading to product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Seep
A cold seep (sometimes called a cold vent) is an area of the ocean floor where seepage of fluids rich in hydrogen sulfide, methane, and other hydrocarbons occurs, often in the form of a brine pool. ''Cold'' does not mean that the temperature of the seepage is lower than that of the surrounding sea water; on the contrary, its temperature is often slightly higher. The "cold" is relative to the very warm (at least ) conditions of a hydrothermal vent. Cold seeps constitute a biome supporting several endemic species. Cold seeps develop unique topography over time, where reactions between methane and seawater create carbonate rock formations and reefs. These reactions may also be dependent on bacterial activity. Ikaite, a hydrous calcium carbonate, can be associated with oxidizing methane at cold seeps. Types Types of cold seeps can be distinguished according to the depth, as shallow cold seeps and deep cold seeps. Cold seeps can also be distinguished in detail, as follow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movile Cave
Movile Cave () is a cave near Mangalia, Constanța County, Romania discovered in 1986 by Cristian Lascu during construction work a few kilometers from the Black Sea coast. It is notable for its unique subterranean groundwater ecosystem abundant in hydrogen sulfide and carbon dioxide, but low in oxygen. Life in the cave has been separated from the outside for the past 5.5 million years and it is based completely on chemosynthesis. Due to its extreme environment, access to Movile Cave is strictly controlled, and a limited number of researchers have permission to study its conditions. Similar caves where life partly or fully depends on chemosynthesis have been found in Ein-Nur Cave and Ayalon Cave (Palestine), Frasassi Caves (Italy), Melissotrypa Cave (Elassona municipality, Greece), Tashan Cave (Iran), caves in the Sharo-Argun Valley in the Caucasus Mountains, Lower Kane Cave and Cesspool Cave (Wyoming and Alleghany County, VA, USA), and Villa Luz Cave (Mexico). Descript ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Vent
Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspots. The dispersal of hydrothermal fluids throughout the global ocean at active vent sites creates hydrothermal plumes. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents. Hydrothermal vents exist because the Earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, they may form features called black smokers or white smokers, which deliver a wide range of elements to the world's oceans, thus contributing to global marine biogeochemistry. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Fixation
Biological carbon fixation, or сarbon assimilation, is the Biological process, process by which living organisms convert Total inorganic carbon, inorganic carbon (particularly carbon dioxide, ) to Organic compound, organic compounds. These organic compounds are then used to store energy and as structures for other Biomolecule, biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use chemosynthesis in the absence of sunlight. Chemosynthesis is carbon fixation driven by chemical energy rather than from sunlight. The process of biological carbon fixation plays a crucial role in the global carbon cycle, as it serves as the primary mechanism for removing from the atmosphere and incorporating it into Biomass (ecology), living biomass. The primary production of organic compounds allows carbon to enter the biosphere. Carbon is considered essential for life as a base element for building organic compounds. The flow of carbon from the Earth's atmosphere, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signalling molecule. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers; this process is commonly known as anaerobic digestio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Tube Worm
''Riftia pachyptila'', commonly known as the giant tube worm and less commonly known as the giant beardworm, is a marine invertebrate in the phylum Annelida (formerly grouped in phylum Pogonophora and Vestimentifera) related to tube worms commonly found in the intertidal and pelagic zones. ''R. pachyptila'' lives on the floor of the Pacific Ocean near hydrothermal vents. The vents provide a natural ambient temperature in their environment ranging from 2 to 30 °C, and this organism can tolerate extremely high hydrogen sulfide levels. These worms can reach a length of , and their tubular bodies have a diameter of . Its common name "giant tube worm" is, however, also applied to the largest living species of shipworm, '' Kuphus polythalamius'', which despite the name "worm", is a bivalve mollusc rather than an annelid. Discovery ''R. pachyptila'' was discovered in 1977 on an expedition of the American bathyscaphe DSV ''Alvin'' to the Galápagos Rift led by geologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotroph
A chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic ( chemoorganotrophs) or inorganic ( chemolithotrophs). The chemotroph designation is in contrast to phototrophs, which use photons. Chemotrophs can be either autotrophic or heterotrophic. Chemotrophs can be found in areas where electron donors are present in high concentration, for instance around hydrothermal vents. Chemoautotroph Chemoautotrophs are autotrophic organisms that can rely on chemosynthesis, i.e. deriving biological energy from chemical reactions of environmental inorganic substrates and synthesizing all necessary organic compounds from carbon dioxide. Chemoautotrophs can use inorganic energy sources such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia or organic sources to produce energy. Most chemoautotrophs are prokaryotic extremophiles, bacteria, or archaea that live in o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophosome
A trophosome is a highly vascularised organ found in some animals that houses symbiotic bacteria that provide food for their host. Trophosomes are contained by the coelom of tube worms (family Siboglinidae, e.g. the giant tube worm ''Riftia pachyptila'') and in the body of symbiotic flatworms of the genus ''Paracatenula''. Organization Initially, the trophosome in Frenulata, frenulates and vestimentiferans, which are now classified as members of the Siboglinidae, had been identified as a mesodermal tissue. The discovery of bacteria inside the trophosomal tissue only occurred in 1981 when the ultrastructure of trophosome of several frenulate species and of ''Sclerolinum brattstromi'' was studied. The bacteriocytes and Symbiosis, symbionts composed of 70.5% and 24.1% of the trophosome's volume respectively. Generally, trophosome extends over the entire trunk region between the two longitudinal blood vessels from immediately posterior to the ventral ciliary band of the forepart to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whale Fall
A whale fall occurs when the Carrion, carcass of a whale has fallen onto the ocean floor, typically at a depth greater than , putting them in the Bathyal zone, bathyal or abyssal zones. On the sea floor, these carcasses can create complex localized ecosystems that supply sustenance to deep-sea organisms for decades. In some circumstances, particularly in cases with lower water temperatures, they can be found at much Mesopelagic zone, shallower depths, with at least one natural instance recorded at 150 m (500 ft) and multiple experimental instances in the range of . Whale falls were first observed in the late 1970s with the development of Deep-sea exploration, deep-sea robotic exploration. Since then, several natural and experimental whale falls have been monitored through the use of observations from submersibles and remotely operated underwater vehicles (Remotely operated underwater vehicle, ROVs) in order to understand patterns of ecological succession on the deep seafloor. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venenivibrio
''Venenivibrio stagnispumantis'' strain CP.B2 is the first microorganisms isolated from the terrestrial hot spring Champagne Pool (75 °C, pH 5.5) in Waiotapu, New Zealand. Morphology The cells are motile and slightly curved rods (1.04 to 1.56 μm long and 0.33 to 0.41 μm wide). Growth conditions The novel bacterium is an obligate chemolithotroph capable of utilizing H2 as electron donor, O2 as corresponding electron acceptor and CO2 as carbon source. ''Venenivibrio stagnispumantis'' gains metabolic energy using the "Knallgas" reaction H2 + ½ O2 → H2O. For growth either elemental sulphur (S0) or thiosulfate (S2O32−) is required. Growth is observed under thermophilic conditions between 45 °C and 75 °C (optimum 70 °C), under moderate acidophilic conditions between pH 4.8 and 5.8 (optimum pH 5.4) and under microaerophilic conditions between 1.0% and 10.0% (v/v) O2 (optimum between 4.0% and 8.0% (v/v) O2). Phylogeny Phylogenetic analysis b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, etc.). In the form of proteins, amino-acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Chela-Flores
Julian Chela-Flores (born 13 June 1942) is a Venezuelan astrobiologist and physicist. He is known for his contributions to the field of planetary habitability. Biography His father, Raimundo Chela a mathematician of Lebanese family, encouraged his studies in science, while his mother raised his interest in the humanities. He lived in England where he studied in the University of London, obtaining a PhD in Quantum Mechanics in 1969. His field of research is astrobiology, in other words the science of the origin, evolution, distribution and destiny of life in the universe, especially life on Europa, the Jovian satellite. From 1971 till 1990 he worked in academic matters continually, especially in research at the Centre of Physics, the Venezuelan Institute for Scientific Research (Full Researcher 1978) and at the Physics Department, Simon Bolivar University (Full Professor 1980), both in Caracas. He is Full Professor ad honorem at the Institute for Advanced Studies (IDEA, Cara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
