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Deinococcus Geothermalis
''Deinococcus geothermalis'' is a non-pathogenic, sphere-shaped, Gram-positive bacteria, Gram-positive, heterotrophic bacterium, where geothermalis means 'hot earth' or 'hot springs'. This bacterium was first obtained from the hot springs of Agnano, Naples, Italy and São Pedro do Sul, Portugal. It resides primarily in hot springs and in deep ocean environments. Genome Structure ''Deinococcus geothermalis'' has a genome that contains 2.47 Mbp with 2,335 protein coding genes. There are 73 insertion sequences (IS) contained in the genome, with 19 different types of ISs'. Upon oxidative stress these ISs' are actively transposed in the bacterium. Additionally, it carries at least 2 plasmids. Growth Characteristics ''Deniococcus geothermalis'' form tetrads when dividing. The size of their cells range from 1.2 - 2.0μm in diameter. It produces orange-pigmented colonies and has an optimum growth temperature of about to , which is the limit between mesophile and thermophile organis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremophile
An extremophile (from Latin ' meaning "extreme" and Greek ' () meaning "love") is an organism that is able to live (or in some cases thrive) in extreme environments, i.e. environments that make survival challenging such as due to extreme temperature, radiation, salinity, or pH level. These organisms are ecologically dominant in the evolutionary history of the planet. Some spores and cocooned bacteria samples have been dormant for more than 40 million years, extremophiles have continued to thrive in the most extreme conditions, making them one of the most abundant lifeforms. Characteristics In the 1980s and 1990s, biologists found that microbial life has great flexibility for surviving in extreme environments—niches that are acidic, extraordinarily hot or within irregular air pressure for example—that would be completely inhospitable to complex organisms. Some scientists even concluded that life may have begun on Earth in hydrothermal vents far under the ocean's su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zvezda (ISS Module)
''Zvezda'' (russian: Звезда, meaning "star"), ''Salyut'' DOS-8, also known as the ''Zvezda'' Service Module, is a module of the International Space Station (ISS). It was the third module launched to the station, and provided all of the station's life support systems, some of which are supplemented in the US Orbital Segment (USOS), as well as living quarters for two crew members. It is the structural and functional center of the Russian Orbital Segment (ROS), which is the Russian part of the ISS. Crew assemble here to deal with emergencies on the station. The module was manufactured in the USSR by RKK Energia, with major sub-contracting work by GKNPTs Khrunichev. ''Zvezda'' was launched on a Proton launch vehicle on 12 July 2000, and docked with the '' Zarya'' module on 26 July 2000. Origins The basic structural frame of ''Zvezda'', known as "DOS-8", was initially built in the mid-1980s to be the core of the '' Mir-2'' space station. This means that ''Zvezda' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progress M-23M
Progress M-23M (russian: Прогресс М-23М, italic=yes), identified by NASA as Progress 55P, is a Progress spacecraft used by Roskosmos to resupply the International Space Station (ISS) during 2014. Progress M-23M was launched on a six-hours rendezvous profile towards the ISS. The 23rd Progress-M 11F615A60 spacecraft to be launched, it had the serial number 423 and was built by RKK Energia. Launch The spacecraft was launched on 9 April 2014 at 15:26:27 UTC from the Baikonur Cosmodrome in Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia Russia (, , ), or the Russian Federation, is a transcontinental coun .... Docking Progress M-23M docked with the Pirs docking compartment on 9 April 2014 at 21:14 UTC, less than six hours after launch. Cargo The Progress spacecraft carries 2383 kg of cargo and supplies to the International Space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EXPOSE
Expose, exposé, or exposed may refer to: News sources * Exposé (journalism), a form of investigative journalism * '' The Exposé'', a British conspiracist website Film and TV Film * ''Exposé'' (film), a 1976 thriller film * ''Exposed'' (1932 film), a 1932 film starring Barbara Kent * ''Exposed'' (1938 film), a 1938 film starring Glenda Farrell * ''Exposed'' (1947 film), a 1947 film starring Adele Mara * ''Exposed'' (1983 film), a 1983 film starring Nastassja Kinski * ''Exposed'' (2003 film), a 2003 American independent comedy film * ''Exposed'' (2011 film), a 2011 film starring Jodi Lyn O'Keefe * ''Exposed'' (2016 film), a 2016 film starring Keanu Reeves Television * "Exposé" (''Lost''), a 2007 episode of ''Lost'' * '' Exposé: America's Investigative Reports'', a PBS news/documentary series * '' eXposed'', the pilot of the American television show ''The Gifted'' * ''Exposed'' (U.S. game show), a 2007 American dating game show that aired on MTV * ''Exposed'' (Canadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superoxide Dismutase
Superoxide dismutase (SOD, ) is an enzyme that alternately catalyzes the dismutation (or partitioning) of the superoxide () radical into ordinary molecular oxygen (O2) and hydrogen peroxide (). Superoxide is produced as a by-product of oxygen metabolism and, if not regulated, causes many types of cell damage. Hydrogen peroxide is also damaging and is degraded by other enzymes such as catalase. Thus, SOD is an important antioxidant defense in nearly all living cells exposed to oxygen. One exception is '' Lactobacillus plantarum'' and related lactobacilli, which use a different mechanism to prevent damage from reactive . Chemical reaction SODs catalyze the disproportionation of superoxide: : 2 HO2 → O2 + H2O2 In this way, is converted into two less damaging species. The pathway by which SOD-catalyzed dismutation of superoxide may be written, for Cu,Zn SOD, with the following reactions: * Cu2+-SOD + → Cu+-SOD + O2 (reduction of copper; oxidation of superoxide) * Cu+-S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalase
Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Catalase has one of the highest turnover numbers of all enzymes; one catalase molecule can convert millions of hydrogen peroxide molecules to water and oxygen each second. Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. It contains four iron-containing heme groups that allow the enzyme to react with hydrogen peroxide. The optimum pH for human catalase is approximately 7, and has a fairly broad maximum: the rate of reaction does not change appreciably between pH 6.8 and 7.5. The pH optimum for other catalases varies between 4 and 11 depending on the species. The optimum temperature also varies by species. Structure Human catalase forms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactive Oxygen Species
In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () produces superoxide (), which is the precursor to most other reactive oxygen species: :O2 + e^- -> \ ^\bullet O2- Dismutation of superoxide produces hydrogen peroxide (): :2 H+ + \ ^\bullet O2^- + \ ^\bullet O2^- -> H2O2 + O2 Hydrogen peroxide in turn may be partially reduced, thus forming hydroxide ions and hydroxyl radicals (), or fully reduced to water: :H2O2 + e^- -> HO^- + \ ^\bullet OH :2 H+ + 2 e- + H2O2 -> 2 H2O In a biological context, ROS are byproducts of the normal metabolism of oxygen. ROS have roles in cell signaling and homeostasis. ROS are intrinsic to cellular functioning, and are present at low and stationary levels in normal cells. In plants, ROS are involved in metabolic processes related to photoprotection a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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