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Hyperthermophile
A hyperthermophile is an organism that thrives in extremely hot environments—from 60 °C (140 °F) upward. An optimal temperature for the existence of hyperthermophiles is often above 80 °C (176 °F). Hyperthermophiles are often within the domain Archaea, although some bacteria are also able to tolerate extreme temperatures. Some of these bacteria are able to live at temperatures greater than 100 °C, deep in the ocean where high pressures increase the boiling point of water. Many hyperthermophiles are also able to withstand other environmental extremes, such as high acidity or high radiation levels. Hyperthermophiles are a subset of extremophiles. Their existence may support the possibility of extraterrestrial life, showing that life can thrive in environmental extremes. History Hyperthermophiles isolated from hot springs in Yellowstone National Park were first reported by Thomas D. Brock in 1965. Since then, more than 70 species have been established. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even though the domain Archaea Cladistics, cladistically includes eukaryotes, the term "archaea" (: archaeon , from the Greek "ἀρχαῖον", which means ancient) in English still generally refers specifically to prokaryotic members of Archaea. Archaea were initially Taxonomy (biology), classified as bacteria, receiving the name archaebacteria (, in the Archaebacteria Kingdom (biology), kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from Bacteria and Eukaryote, Eukaryota. Archaea are further divided into multiple recognized phylum, phyla. Classification is difficult because most have not been Isolation (microbiology), isolated in a laboratory and have been detected only by their Gene, gene s ... [...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] |
Extremophile
An extremophile () is an organism that is able to live (or in some cases thrive) in extreme environments, i.e., environments with conditions approaching or stretching the limits of what known life can adapt to, such as extreme temperature, pressure, radiation, salinity, or pH level. Since the definition of an extreme environment is relative to an arbitrarily defined standard, often an anthropocentric one, these organisms can be considered Dominance (ecology), ecologically dominant in the evolutionary history of the planet. Dating back to more than 40 million years ago, extremophiles have continued to thrive in the most extreme conditions, making them one of the most abundant lifeforms. The study of extremophiles has expanded human knowledge of the limits of life, and informs speculation about extraterrestrial life. Extremophiles are also of interest because of their potential for bioremediation of environments made hazardous to humans due to pollution or contamination. Character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone National Park
Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd United States Congress, 42nd U.S. Congress through the Yellowstone National Park Protection Act and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the US, and is also widely understood to be the first national park in the world. The park is known for List of animals of Yellowstone, its wildlife and Geothermal areas of Yellowstone, its many geothermal features, especially the Old Faithful geyser, one of its most popular. While it represents many types of biomes, the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion. While Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by Mountain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanopyrus
''Methanopyrus'' is a genus of methanogen, with a single described species, ''Methanopyrus kandleri''. It is a rod-shaped hyperthermophile, discovered on the wall of a black smoker from the Gulf of California at a depth of 2,000 m, at temperatures of 84–110 °C. Strain 116 was discovered in black smoker fluid of the Kairei vent field, Kairei hydrothermal field; it can survive and reproduce at 122 °C. ''M. kandleri'' also requires a high ionic concentration (>1 Molar (unit), M) in order for growth and cellular activity. Due to the species' high resilience and extreme environment, ''M. kandleri'' is also classified as an extremophile. It lives in a hydrogen–carbon dioxide rich environment, and like other methanogens reduces the latter to methane. It is placed among the Euryarchaeota, in its own class. Microbiological characteristics Morphology ''Methanopyrus kandleri'' is a rod-shaped methanogen with an approximate length of 2–14 μm and diameter of 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysozyme
Lysozyme (, muramidase, ''N''-acetylmuramide glycanhydrolase; systematic name peptidoglycan ''N''-acetylmuramoylhydrolase) is an antimicrobial enzyme produced by animals that forms part of the innate immune system. It is a glycoside hydrolase that catalyzes the following process: : Hydrolysis of (1→4)-β-linkages between ''N''-acetylmuramic acid and ''N''-acetyl-D-glucosamine residues in a peptidoglycan and between ''N''-acetyl-D-glucosamine residues in chitodextrins Peptidoglycan is the major component of gram-positive bacterial cell wall. This hydrolysis in turn compromises the integrity of bacterial cell walls causing lysis of the bacteria. Lysozyme is abundant in secretions including tears, saliva, human milk, and mucus. It is also present in cytoplasmic granules of the macrophages and the polymorphonuclear neutrophils (PMNs). Large amounts of lysozyme can be found in egg white. C-type lysozymes are closely related to alpha-lactalbumin, α-lactalbumin in sequence and st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycerol
Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pharmaceutical formulations. Because of its three hydroxyl groups, glycerol is miscible with water and is Hygroscopy, hygroscopic in nature. Modern use of the word glycerine (alternatively spelled glycerin) refers to commercial preparations of less than 100% purity, typically 95% glycerol. Structure Although chirality, achiral, glycerol is prochirality, prochiral with respect to reactions of one of the two primary alcohols. Thus, in substituted derivatives, the Glycerophospholipid#Nomenclature and stereochemistry, stereospecific numbering labels the molecule with a ''sn''- prefix before the stem name of the molecule. Production Natural sources Glycerol is generally obtained from plant and animal sources where it occurs in triglycerides, est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprene
Isoprene, or 2-methyl-1,3-butadiene, is a common volatile organic compound with the formula CH2=C(CH3)−CH=CH2. In its pure form it is a colorless volatile liquid. It is produced by many plants and animals (including humans) and its polymers are the main component of natural rubber. History and etymology Charles Greville Williams, C. G. Williams named the compound in 1860 after obtaining it from the pyrolysis of natural rubber. He correctly deduced the mass shares of carbon and hydrogen (but arrived at an incorrect formula C10H8 because the modern atomic weight of carbon was not adopted until the Karlsruhe Congress held later that year). He did not specify the reasons for the name, but it is hypothesized that it came from "propylene" with which isoprene shares some physical and chemical properties. The first one to observe recombination of isoprene into rubber-like substance was in 1879, and William A. Tilden identified its structure five years later. Natural occurrences Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entner–Doudoroff Pathway
The Entner–Doudoroff pathway (ED Pathway) is a metabolic pathway that is most notable in Gram-negative bacteria, certain Gram-positive bacteria and archaea. Glucose is the substrate in the ED pathway and, through a series of enzyme assisted chemical reactions, is catabolized into pyruvate. Entner and Doudoroff (1952) and MacGee and Doudoroff (1954) first reported the ED pathway in the bacterium '' Pseudomonas saccharophila''. While originally thought to be just an alternative to glycolysis (EMP) and the pentose phosphate pathway (PPP), some studies now suggest that the original role of the EMP may have originally been about anabolism and repurposed over time to catabolism, meaning the ED pathway may be the older pathway. Recent studies have also shown the prevalence of the ED pathway may be more widespread than first predicted with evidence supporting the presence of the pathway in cyanobacteria, ferns, algae, mosses, and plants.Chen, Xi, et al. "The Entner–Doudoroff pathway i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone
In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei and in most Archaeal phyla. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn are wrapped into 30- nanometer fibers that form tightly packed chromatin. Histones prevent DNA from becoming tangled and protect it from DNA damage. In addition, histones play important roles in gene regulation and DNA replication. Without histones, unwound DNA in chromosomes would be very long. For example, each human cell has about 1.8 meters of DNA if completely stretched out; however, when wound about histones, this length is reduced to about 9 micrometers (0.09 mm) of 30 nm diameter chromatin fibers. There are five families of histones, which are designated H1/H5 (linker histones), H2, H3, and H4 (core histones). The nucleosome core is formed of two H2A-H2B dimers and a H3-H4 tetramer. The tight wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denaturation (biochemistry)
In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation, radiation, or heat. If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death. Protein denaturation is also a consequence of cell death. Denatured proteins can exhibit a wide range of characteristics, from conformational change and loss of solubility or dissociation of cofactors to aggregation due to the exposure of hydrophobic groups. The loss of solubility as a result of denaturation is called ''coagulation''. Denatured proteins, e.g., metalloenzymes, lose their 3D structure or metal cofactor, and therefore, cannot function. Proper protein folding is key to whether a globular or memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
