1.
Electron
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The electron is a subatomic particle, symbol e− or β−, with a negative elementary electric charge. Electrons belong to the first generation of the lepton particle family, the electron has a mass that is approximately 1/1836 that of the proton. Quantum mechanical properties of the include a intrinsic angular momentum of a half-integer value, expressed in units of the reduced Planck constant. As it is a fermion, no two electrons can occupy the same state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of particles and waves, they can collide with other particles and can be diffracted like light. Since an electron has charge, it has an electric field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law, electrons radiate or absorb energy in the form of photons when they are accelerated. Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields, special telescopes can detect electron plasma in outer space. Electrons are involved in applications such as electronics, welding, cathode ray tubes, electron microscopes, radiation therapy, lasers, gaseous ionization detectors. Interactions involving electrons with other particles are of interest in fields such as chemistry. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms, ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the cause of chemical bonding. In 1838, British natural philosopher Richard Laming first hypothesized the concept of a quantity of electric charge to explain the chemical properties of atoms. Irish physicist George Johnstone Stoney named this charge electron in 1891, electrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of isotopes and in high-energy collisions. The antiparticle of the electron is called the positron, it is identical to the electron except that it carries electrical, when an electron collides with a positron, both particles can be totally annihilated, producing gamma ray photons. The ancient Greeks noticed that amber attracted small objects when rubbed with fur, along with lightning, this phenomenon is one of humanitys earliest recorded experiences with electricity. In his 1600 treatise De Magnete, the English scientist William Gilbert coined the New Latin term electricus, both electric and electricity are derived from the Latin ēlectrum, which came from the Greek word for amber, ἤλεκτρον
2.
Hydrogen
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Hydrogen is a chemical element with chemical symbol H and atomic number 1. With a standard weight of circa 1.008, hydrogen is the lightest element on the periodic table. Its monatomic form is the most abundant chemical substance in the Universe, non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed protium, has one proton, the universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. Hydrogen plays an important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a charge when it is known as a hydride. The hydrogen cation is written as though composed of a bare proton, Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals. Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production, the two largest uses being fossil fuel processing and ammonia production, mostly for the fertilizer market, Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks. Hydrogen gas is flammable and will burn in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion is −286 kJ/mol,2 H2 + O2 →2 H2O +572 kJ Hydrogen gas forms explosive mixtures with air in concentrations from 4–74%, the explosive reactions may be triggered by spark, heat, or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C, the detection of a burning hydrogen leak may require a flame detector, such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames, the destruction of the Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated. The visible orange flames in that incident were the result of a mixture of hydrogen to oxygen combined with carbon compounds from the airship skin. H2 reacts with every oxidizing element, the ground state energy level of the electron in a hydrogen atom is −13.6 eV, which is equivalent to an ultraviolet photon of roughly 91 nm wavelength. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, however, the atomic electron and proton are held together by electromagnetic force, while planets and celestial objects are held by gravity. The most complicated treatments allow for the effects of special relativity
3.
Photosynthesis
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Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities. In most cases, oxygen is released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis, such organisms are called photoautotrophs, in plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, in the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate. Using the ATP and NADPH produced by the light-dependent reactions, the compounds are then reduced and removed to form further carbohydrates. Cyanobacteria appeared later, the oxygen they produced contributed directly to the oxygenation of the Earth. Today, the rate of energy capture by photosynthesis globally is approximately 130 terawatts. Photosynthetic organisms also convert around 100–115 thousand million tonnes of carbon into biomass per year. Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide, however, not all organisms that use light as a source of energy carry out photosynthesis, photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon. In plants, algae, and cyanobacteria, photosynthesis releases oxygen and this is called oxygenic photosynthesis and is by far the most common type of photosynthesis used by living organisms. Although there are differences between oxygenic photosynthesis in plants, algae, and cyanobacteria, the overall process is quite similar in these organisms. There are also varieties of anoxygenic photosynthesis, used mostly by certain types of bacteria. Carbon dioxide is converted into sugars in a process called carbon fixation, photosynthesis provides the energy in the form of free electrons that are used to split carbon from carbon dioxide that is then used to fix that carbon once again as carbohydrate. Carbon fixation is a redox reaction, so photosynthesis supplies the energy that drives both process. In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make the energy-storage molecules ATP, during the second stage, the light-independent reactions use these products to capture and reduce carbon dioxide. Most organisms that utilize oxygenic photosynthesis use visible light for the light-dependent reactions, some organisms employ even more radical variants of photosynthesis. Some archea use a method that employs a pigment similar to those used for vision in animals. The bacteriorhodopsin changes its configuration in response to sunlight, acting as a proton pump and this produces a proton gradient more directly, which is then converted to chemical energy
4.
Mitochondrion
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The mitochondrion is a double membrane-bound organelle found in all eukaryotic organisms. Some cells in multicellular organisms may however lack them. A number of organisms, such as microsporidia, parabasalids. To date, only one eukaryote, Monocercomonoides, is known to have completely lost its mitochondria, the word mitochondrion comes from the Greek μίτος, mitos, thread, and χονδρίον, chondrion, granule or grain-like. Mitochondria generate most of the supply of adenosine triphosphate, used as a source of chemical energy. Mitochondria are commonly between 0.75 and 3 μm in diameter but vary considerably in size and structure, unless specifically stained, they are not visible. Mitochondrial biogenesis is in turn temporally coordinated with these cellular processes, Mitochondria have been implicated in several human diseases, including mitochondrial disorders, cardiac dysfunction, heart failure and autism. The number of mitochondria in a cell can vary widely by organism, tissue, for instance, red blood cells have no mitochondria, whereas liver cells can have more than 2000, The organelle is composed of compartments that carry out specialized functions. These compartments or regions include the outer membrane, the space, the inner membrane. Although most of a cells DNA is contained in the cell nucleus, mitochondrial proteins vary depending on the tissue and the species. In humans,615 distinct types of protein have been identified from cardiac mitochondria, the mitochondrial proteome is thought to be dynamically regulated. The first observations of structures that probably represented mitochondria were published in the 1840s. Richard Altmann, in 1890, established them as cell organelles, the term mitochondria was coined by Carl Benda in 1898. Leonor Michaelis discovered that Janus green can be used as a stain for mitochondria in 1900. Benjamin F. Kingsbury, in 1912, first related them with cell respiration, in 1913, particles from extracts of guinea-pig liver were linked to respiration by Otto Heinrich Warburg, which he called grana. Warburg and Heinrich Otto Wieland, who had postulated a similar particle mechanism. It was not until 1925, when David Keilin discovered cytochromes, in the following years, the mechanism behind cellular respiration was further elaborated, although its link to the mitochondria was not known. The introduction of tissue fractionation by Albert Claude allowed mitochondria to be isolated from other cell fractions, in 1946, he concluded that cytochrome oxidase and other enzymes responsible for the respiratory chain were isolated to the mitchondria
5.
Deuterium
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Deuterium is one of two stable isotopes of hydrogen. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen isotope, Deuterium has a natural abundance in Earths oceans of about one atom in 6420 of hydrogen. Thus deuterium accounts for approximately 0. 0156% of all the naturally occurring hydrogen in the oceans, the abundance of deuterium changes slightly from one kind of natural water to another. The deuterium isotopes name is formed from the Greek deuteros meaning second, Deuterium was discovered and named in 1931 by Harold Urey. When the neutron was discovered in 1932, this made the structure of deuterium obvious. Soon after deuteriums discovery, Urey and others produced samples of water in which the deuterium content had been highly concentrated. Deuterium is destroyed in the interiors of stars faster than it is produced, other natural processes are thought to produce only an insignificant amount of deuterium. Nearly all deuterium found in nature was produced in the Big Bang 13.8 billion years ago and this is the ratio found in the gas giant planets, such as Jupiter. However, other bodies are found to have different ratios of deuterium to hydrogen-1. This is thought to be as a result of natural isotope separation processes that occur from solar heating of ices in comets, like the water-cycle in Earths weather, such heating processes may enrich deuterium with respect to protium. The analysis of ratios in comets found results very similar to the mean ratio in Earths oceans. This reinforces theories that much of Earths ocean water is of cometary origin, the deuterium/protium ratio of the comet 67P/Churyumov-Gerasimenko, as measured by the Rosetta space probe, is about three times that of earth water. This figure is the highest yet measured in a comet, deuterium/protium ratios thus continue to be an active topic of research in both astronomy and climatology. Deuterium is frequently represented by the chemical symbol D, since it is an isotope of hydrogen with mass number 2, it is also represented by 2H. IUPAC allows both D and 2H, although 2H is preferred, a distinct chemical symbol is used for convenience because of the isotopes common use in various scientific processes. In quantum mechanics the energy levels of electrons in atoms depend on the mass of the system of electron. For hydrogen, this amount is about 1837/1836, or 1.000545, the energies of spectroscopic lines for deuterium and light-hydrogen therefore differ by the ratios of these two numbers, which is 1.000272. The wavelengths of all deuterium spectroscopic lines are shorter than the lines of light hydrogen
6.
ATP synthase
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ATP synthase is an important enzyme that creates the energy storage molecule adenosine triphosphate. ATP is the most commonly used energy currency of cells for most organisms and it is formed from adenosine diphosphate and inorganic phosphate, and needs energy for its formation. Located within the membrane and the inner mitochondrial membrane, ATP synthase consists of two regions the FO portion embedded within the membrane. The F1 portion of the ATP synthase is outside the membrane, the nomenclature of the enzyme has a long history. These functional regions consist of different protein subunits — refer to tables, the F1 particle is large and can be seen in the transmission electron microscope by negative staining. These are particles of 9 nm diameter that pepper the inner mitochondrial membrane and this ATPase activity was further associated with the creation of ATP by a long series of experiments in many laboratories. The FO region of ATP synthase is a pore that is embedded in the mitochondrial membrane. It consists of three main subunits A, B, and C, and six additional subunits, d, e, f, g, F6, and 8. The research group of John E. Walker, then at the MRC Laboratory of Molecular Biology in Cambridge, the structure, at the time the largest asymmetric protein structure known, indicated that Boyers rotary-catalysis model was, in essence, correct. For elucidating this, Boyer and Walker shared half of the 1997 Nobel Prize in Chemistry, the crystal structure of the F1 showed alternating alpha and beta subunits, arranged like segments of an orange around a rotating asymmetrical gamma subunit. A portion of the FO rotates as the pass through the membrane. The major F1 subunits are prevented from rotating in sympathy with the central stalk rotor by a stalk that joins the alpha3beta3 to the non-rotating portion of FO. The structure of the intact ATP synthase is currently known at low-resolution from electron cryo-microscopy studies of the complex, the cryo-EM model of ATP synthase suggests that the peripheral stalk is a flexible structure that wraps around the complex as it joins F1 to FO. Under the right conditions, the reaction can also be carried out in reverse. The binding change mechanism involves the active site of a β subunits cycling between three states, in the open state, ADP and phosphate enter the active site, in the adjacent diagram, this is shown in red. The protein then closes up around the molecules and binds them loosely — the loose state, finally, the active site cycles back to the open state, releasing ATP and binding more ADP and phosphate, ready for the next cycle of ATP production. Like other enzymes, the activity of F1FO ATP synthase is reversible, the overall process of creating energy in this fashion is termed oxidative phosphorylation. The same process takes place in the mitochondria, where ATP synthase is located in the mitochondrial membrane
7.
Acid
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An acid is a molecule or ion capable of donating a hydron, or, alternatively, capable of forming a covalent bond with an electron pair. The first category of acids is the donors or Brønsted acids. In the special case of solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents, acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals to form salts. The word acid is derived from the Latin acidus/acēre meaning sour, an aqueous solution of an acid has a pH less than 7 and is colloquially also referred to as acid, while the strict definition refers only to the solute. A lower pH means a higher acidity, and thus a higher concentration of hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic, common aqueous acids include hydrochloric acid, acetic acid, sulfuric acid, and citric acid. As these examples show, acids can be solutions or pure substances, strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid. The second category of acids are Lewis acids, which form a covalent bond with an electron pair, however, hydrogen chloride, acetic acid, and most other Brønsted-Lowry acids cannot form a covalent bond with an electron pair and are therefore not Lewis acids. Conversely, many Lewis acids are not Arrhenius or Brønsted-Lowry acids, in modern terminology, an acid is implicitly a Brønsted acid and not a Lewis acid, since chemists almost always refer to a Lewis acid explicitly as a Lewis acid. Modern definitions are concerned with the chemical reactions common to all acids. Most acids encountered in life are aqueous solutions, or can be dissolved in water, so the Arrhenius. The Brønsted-Lowry definition is the most widely used definition, unless otherwise specified, hydronium ions are acids according to all three definitions. Interestingly, although alcohols and amines can be Brønsted-Lowry acids, they can function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms. The Swedish chemist Svante Arrhenius attributed the properties of acidity to hydrogen ions or protons in 1884, an Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in the water. Thus, an Arrhenius acid can also be described as a substance that increases the concentration of ions when added to water. Examples include molecular substances such as HCl and acetic acid, an Arrhenius base, on the other hand, is a substance which increases the concentration of hydroxide ions when dissolved in water. Thus, an Arrhenius acid could also be said to be one that decreases hydroxide concentration, in an acidic solution, the concentration of hydronium ions is greater than 10−7 moles per liter
8.
Tritium
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Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons, naturally occurring tritium is extremely rare on Earth, where trace amounts are formed by the interaction of the atmosphere with cosmic rays. It can be produced by irradiating lithium metal or lithium bearing ceramic pebbles in a nuclear reactor, the name of this isotope is derived from the Greek word τρίτος meaning third. While tritium has several different experimentally determined values of its half-life and it decays into helium-3 by beta decay as in this nuclear equation, and it releases 18.6 keV of energy in the process. The electrons kinetic energy varies, with an average of 5.7 keV, beta particles from tritium can penetrate only about 6.0 mm of air, and they are incapable of passing through the dead outermost layer of human skin. The unusually low energy released in the beta decay makes the decay appropriate for absolute neutrino mass measurements in the laboratory. The low energy of tritiums radiation makes it difficult to detect tritium-labeled compounds except by using liquid scintillation counting, Tritium is produced in nuclear reactors by neutron activation of lithium-6. This is possible with neutrons of any energy, and is an exothermic reaction yielding 4.8 MeV, in comparison, the fusion of deuterium with tritium releases about 17.6 MeV of energy. High-energy neutrons can produce tritium from lithium-7 in an endothermic reaction. This was discovered when the 1954 Castle Bravo nuclear test produced a high yield. High-energy neutrons irradiating boron-10 will also produce tritium, A more common result of boron-10 neutron capture is 7Li. The reactions requiring high neutron energies are not attractive production methods for peaceful applications, Tritium is also produced in heavy water-moderated reactors whenever a deuterium nucleus captures a neutron. This reaction has a quite small absorption cross section, making water a good neutron moderator. Even so, cleaning tritium from the moderator may be desirable after several years to reduce the risk of its escaping to the environment. Ontario Power Generations Tritium Removal Facility processes up to 2,500 tonnes of water a year. Deuteriums absorption cross section for thermal neutrons is about 0.52 millibarns, whereas that of oxygen-16 is about 0.19 millibarns and that of oxygen-17 is about 240 millibarns. Tritium is a product of the nuclear fission of uranium-235, plutonium-239. The release or recovery of tritium needs to be considered in the operation of reactors, especially in the reprocessing of nuclear fuels
9.
Proton
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A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron. Protons and neutrons, each with masses of one atomic mass unit, are collectively referred to as nucleons. One or more protons are present in the nucleus of every atom, the number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number. Since each element has a number of protons, each element has its own unique atomic number. The word proton is Greek for first, and this name was given to the nucleus by Ernest Rutherford in 1920. In previous years, Rutherford had discovered that the nucleus could be extracted from the nuclei of nitrogen by atomic collisions. Protons were therefore a candidate to be a particle, and hence a building block of nitrogen. In the modern Standard Model of particle physics, protons are hadrons, and like neutrons, although protons were originally considered fundamental or elementary particles, they are now known to be composed of three valence quarks, two up quarks and one down quark. The rest masses of quarks contribute only about 1% of a protons mass, the remainder of a protons mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. At sufficiently low temperatures, free protons will bind to electrons, however, the character of such bound protons does not change, and they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, the result is a protonated atom, which is a chemical compound of hydrogen. In vacuum, when electrons are present, a sufficiently slow proton may pick up a single free electron, becoming a neutral hydrogen atom. Such free hydrogen atoms tend to react chemically with other types of atoms at sufficiently low energies. When free hydrogen atoms react with other, they form neutral hydrogen molecules. Protons are spin-½ fermions and are composed of three quarks, making them baryons. Protons have an exponentially decaying positive charge distribution with a mean square radius of about 0.8 fm. Protons and neutrons are both nucleons, which may be together by the nuclear force to form atomic nuclei. The nucleus of the most common isotope of the atom is a lone proton
10.
Hydrate
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In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understood, in organic chemistry, a hydrate is a compound formed by the addition of water or its elements to another molecule. A molecule of water may be eliminated, for example by the action of sulfuric acid, another example is chloral hydrate, CCl3–CH2, which can be formed by reaction of water with chloral, CCl3–CH=O. Many organic molecules, as well as molecules, form crystals that incorporate water into the crystalline structure without chemical alteration of the organic molecule. The sugar trehalose, for example, exists in both a form and as a dihydrate. Protein crystals commonly have as much as 50% water content, molecules are also labeled as hydrates for historical reasons not covered above. Glucose, C6H12O6, was thought of as C66 and described as a carbohydrate. Methanol is often sold as methyl hydrate, implying the incorrect formula CH3OH2, such hydrates are also said to contain water of crystallization or water of hydration. If the water is water, where the hydrogen involved is the isotope deuterium. A colorful example is cobalt chloride, which turns blue to red upon hydration. The notation hydrated compound⋅nH2O, where n is the number of molecules per formula unit of the salt, is commonly used to show that a salt is hydrated. The n is usually a low integer, though it is possible for fractional values to occur, for example, in a monohydrate n is one, and in a hexahydrate n is 6. Numerical prefixes of Greek origin are, A hydrate which has lost water is referred to as an anhydride, a substance that does not contain any water is referred to as anhydrous. Some anhydrous compounds are hydrated so easily that they are said to be hygroscopic and are used as drying agents or desiccants, clathrate hydrates are water ice with gas molecules trapped within, they are a form of clathrate. An important example is methane hydrate, nonpolar molecules such as methane can form clathrate hydrates with water, especially under high pressure. In such cases the guest-host hydrogen bonds result in the formation of L-type Bjerrum defects in the clathrate lattice, the stability of hydrates is generally determined by the nature of the compounds, their temperature, and the relative humidity
11.
Georg Zundel
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Georg Zundel was a German physical chemist, tenured professor of biophysics at University of Munich, peace activist, environmentalist and philanthropist. His father Georg was a painter and his mother was the daughter of the German industrialist Robert Bosch, as a scientist, a physicist, he achieved a worldwide reputation for hydrogen bond research. He worked closely with colleagues from both the East and the West during the Cold War and he published 313 scientific papers during his academic career. As a philanthropist he established the Berghof Foundation for Conflict Studies in 1971, in this area, he was awarded the Great Cross of Merit of the Federal Republic of Germany, in 2003. Autobiography, „Es muss viel geschehen. “ Berlin, Verlag für Wissenschafts- und Regionalgeschichte Dr. Michael Engel,2006
