3PFN
63-591: NADK may refer to: NAD kinase , an enzyme National Army of Democratic Kampuchea , a Cambodian guerrilla force Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title NADK . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NADK&oldid=933008751 " Category : Disambiguation pages Hidden categories: Short description
126-412: A platinum plate which was used as the anode, the cathode being a platinum wire partially submerged into mercury. Electrolysis then gave calcium–mercury and magnesium–mercury amalgams, and distilling off the mercury gave the metal. However, pure calcium cannot be prepared in bulk by this method and a workable commercial process for its production was not found until over a century later. At 3%, calcium
189-434: A "steady state" with respect to calcium input and output. This has important climatological implications, as the marine calcium cycle is closely tied to the carbon cycle . Many calcium compounds are used in food, as pharmaceuticals, and in medicine, among others. For example, calcium and phosphorus are supplemented in foods through the addition of calcium lactate , calcium diphosphate , and tricalcium phosphate . The last
252-562: A calcium–lead alloy, in making automotive batteries. Calcium is the most abundant metal and the fifth-most abundant element in the human body . As electrolytes , calcium ions (Ca ) play a vital role in the physiological and biochemical processes of organisms and cells : in signal transduction pathways where they act as a second messenger ; in neurotransmitter release from neurons ; in contraction of all muscle cell types; as cofactors in many enzymes ; and in fertilization . Calcium ions outside cells are important for maintaining
315-638: A gas had not been recognised by the ancient Romans. In 1789, Antoine Lavoisier suspected that lime might be an oxide of a fundamental chemical element . In his table of the elements, Lavoisier listed five "salifiable earths" (i.e., ores that could be made to react with acids to produce salts ( salis = salt, in Latin): chaux (calcium oxide), magnésie (magnesia, magnesium oxide), baryte (barium sulfate), alumine (alumina, aluminium oxide), and silice (silica, silicon dioxide)). About these "elements", Lavoisier reasoned: We are probably only acquainted as yet with
378-412: A high pressure of oxygen, and there is some evidence for a yellow superoxide Ca(O 2 ) 2 . Calcium hydroxide, Ca(OH) 2 , is a strong base, though not as strong as the hydroxides of strontium, barium or the alkali metals. All four dihalides of calcium are known. Calcium carbonate (CaCO 3 ) and calcium sulfate (CaSO 4 ) are particularly abundant minerals. Like strontium and barium, as well as
441-508: A part of the metallic substances existing in nature, as all those which have a stronger affinity to oxygen than carbon possesses, are incapable, hitherto, of being reduced to a metallic state, and consequently, being only presented to our observation under the form of oxyds, are confounded with earths. It is extremely probable that barytes, which we have just now arranged with earths, is in this situation; for in many experiments it exhibits properties nearly approaching to those of metallic bodies. It
504-423: A rather high neutron flux to allow short-lived Ca to capture a neutron. Ca is produced by electron capture in the r-process in type Ia supernovae , where high neutron excess and low enough entropy ensures its survival. Ca and Ca are the first "classically stable" nuclides with a 6-neutron or 8-neutron excess respectively. Although extremely neutron-rich for such a light element, Ca is very stable because it
567-401: A result, when Ca does decay, it does so by double beta decay to Ti instead, being the lightest nuclide known to undergo double beta decay. Ca can also theoretically undergo double beta decay to Ti, but this has never been observed. The most common isotope Ca is also doubly magic and could undergo double electron capture to Ar , but this has likewise never been observed. Calcium is
630-473: Is calcium carbonate , found in limestone and the fossilised remnants of early sea life; gypsum , anhydrite , fluorite , and apatite are also sources of calcium. The name derives from Latin calx " lime ", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy , who named
693-503: Is a chemical element ; it has symbol Ca and atomic number 20. As an alkaline earth metal , calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium . It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium . The most common calcium compound on Earth
SECTION 10
#1732856145104756-472: Is a cosmogenic nuclide , continuously produced through neutron activation of natural Ca. Many other calcium radioisotopes are known, ranging from Ca to Ca. They are all much shorter-lived than Ca, the most stable being Ca (half-life 163 days) and Ca (half-life 4.54 days). Isotopes lighter than Ca usually undergo beta plus decay to isotopes of potassium, and those heavier than Ca usually undergo beta minus decay to isotopes of scandium , though near
819-438: Is a doubly magic nucleus , having 20 protons and 28 neutrons arranged in closed shells. Its beta decay to Sc is very hindered because of the gross mismatch of nuclear spin : Ca has zero nuclear spin, being even–even , while Sc has spin 6+, so the decay is forbidden by the conservation of angular momentum . While two excited states of Sc are available for decay as well, they are also forbidden due to their high spins. As
882-497: Is a better conductor by mass than both due to its very low density. While calcium is infeasible as a conductor for most terrestrial applications as it reacts quickly with atmospheric oxygen, its use as such in space has been considered. The chemistry of calcium is that of a typical heavy alkaline earth metal. For example, calcium spontaneously reacts with water more quickly than magnesium and less quickly than strontium to produce calcium hydroxide and hydrogen gas. It also reacts with
945-424: Is also used as a polishing agent in toothpaste and in antacids . Calcium lactobionate is a white powder that is used as a suspending agent for pharmaceuticals. In baking, calcium phosphate is used as a leavening agent . Calcium sulfite is used as a bleach in papermaking and as a disinfectant, calcium silicate is used as a reinforcing agent in rubber, and calcium acetate is a component of liming rosin and
1008-421: Is also used to strengthen aluminium alloys used for bearings, for the control of graphitic carbon in cast iron , and to remove bismuth impurities from lead. Calcium metal is found in some drain cleaners, where it functions to generate heat and calcium hydroxide that saponifies the fats and liquefies the proteins (for example, those in hair) that block drains. Besides metallurgy, the reactivity of calcium
1071-490: Is different from Wikidata All article disambiguation pages All disambiguation pages NAD%2B kinase 65220 192185 ENSG00000008130 ENSMUSG00000029063 O95544 P58058 NM_001353642 NM_001159637 NM_138671 NM_001355599 NP_001340571 NP_001153109 NP_619612 NP_001342528 NAD kinase (EC 2.7.1.23, NADK) is an enzyme that converts nicotinamide adenine dinucleotide (NAD ) into NADP through phosphorylating
1134-452: Is even possible that all the substances we call earths may be only metallic oxyds, irreducible by any hitherto known process. Calcium, along with its congeners magnesium, strontium, and barium, was first isolated by Humphry Davy in 1808. Following the work of Jöns Jakob Berzelius and Magnus Martin af Pontin on electrolysis , Davy isolated calcium and magnesium by putting a mixture of the respective metal oxides with mercury(II) oxide on
1197-505: Is exploited to remove nitrogen from high-purity argon gas and as a getter for oxygen and nitrogen. It is also used as a reducing agent in the production of chromium , zirconium , thorium , vanadium and uranium . It can also be used to store hydrogen gas, as it reacts with hydrogen to form solid calcium hydride , from which the hydrogen can easily be re-extracted. Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes. In particular,
1260-458: Is less reactive than strontium or barium, the oxide–nitride coating that results in air is stable and lathe machining and other standard metallurgical techniques are suitable for calcium. In the United States and Canada, calcium is instead produced by reducing lime with aluminium at high temperatures. Calcium cycling provides a link between tectonics , climate , and the carbon cycle . In
1323-453: Is more complicated and involves the bicarbonate ion (HCO 3 ) that forms when CO 2 reacts with water at seawater pH : At seawater pH, most of the dissolved CO 2 is immediately converted back into HCO 3 . The reaction results in a net transport of one molecule of CO 2 from the ocean/atmosphere into the lithosphere . The result is that each Ca ion released by chemical weathering ultimately removes one CO 2 molecule from
SECTION 20
#17328561451041386-499: Is predominantly found in its oxidized state NAD , the phosphorylated NADP is largely present in its reduced form, as NADPH. Thus, NADK can modulate responses to oxidative stress by controlling NADP synthesis. Bacterial NADK is shown to be inhibited allosterically by both NADPH and NADH. NADK is also reportedly stimulated by calcium / calmodulin binding in certain cell types, such as neutrophils. NAD kinases in plants and sea urchin eggs have also been found to bind calmodulin. Due to
1449-458: Is the fifth most abundant element in the Earth's crust , and the third most abundant metal behind aluminium and iron . It is also the fourth most abundant element in the lunar highlands . Sedimentary calcium carbonate deposits pervade the Earth's surface as fossilized remains of past marine life; they occur in two forms, the rhombohedral calcite (more common) and the orthorhombic aragonite (forming in more temperate seas). Minerals of
1512-425: Is the second-most common isotope. The other four natural isotopes, Ca, Ca, Ca, and Ca, are significantly rarer, each comprising less than 1% of all natural calcium. The four lighter isotopes are mainly products of the oxygen-burning and silicon-burning processes, leaving the two heavier ones to be produced via neutron capture processes. Ca is mostly produced in a "hot" s-process , as its formation requires
1575-492: Is used to make metallic soaps and synthetic resins. Calcium is on the World Health Organization's List of Essential Medicines . Foods rich in calcium include dairy products such as milk and yogurt , cheese , sardines , salmon , soy products, kale , and fortified breakfast cereals . Because of concerns for long-term adverse side effects, including calcification of arteries and kidney stones , both
1638-431: Is very soluble in water, 85% of extracellular calcium is as dicalcium phosphate with a solubility of 2.00 mM , and the hydroxyapatite of bones in an organic matrix is tricalcium phosphate with a solubility of 1000 μM. Calcium is a common constituent of multivitamin dietary supplements , but the composition of calcium complexes in supplements may affect its bioavailability which varies by solubility of
1701-480: The United States (about 2000 to 4000 tonnes per year). Canada and France are also among the minor producers. In 2005, about 24000 tonnes of calcium were produced; about half of the world's extracted calcium is used by the United States, with about 80% of the output used each year. In Russia and China, Davy's method of electrolysis is still used, but is instead applied to molten calcium chloride . Since calcium
1764-418: The carboxyl groups of glutamic acid or aspartic acid residues; through interacting with phosphorylated serine , tyrosine , or threonine residues; or by being chelated by γ-carboxylated amino acid residues. Trypsin , a digestive enzyme, uses the first method; osteocalcin , a bone matrix protein, uses the third. Some other bone matrix proteins such as osteopontin and bone sialoprotein use both
1827-506: The contraction of muscles , nerve conduction, and the clotting of blood. As a result, intra- and extracellular calcium levels are tightly regulated by the body. Calcium can play this role because the Ca ion forms stable coordination complexes with many organic compounds, especially proteins ; it also forms compounds with a wide range of solubilities, enabling the formation of the skeleton . Calcium ions may be complexed by proteins through binding
1890-496: The nuclear drip lines , proton emission and neutron emission begin to be significant decay modes as well. Like other elements, a variety of processes alter the relative abundance of calcium isotopes. The best studied of these processes is the mass-dependent fractionation of calcium isotopes that accompanies the precipitation of calcium minerals such as calcite , aragonite and apatite from solution. Lighter isotopes are preferentially incorporated into these minerals, leaving
1953-455: The oxygen and nitrogen in air to form a mixture of calcium oxide and calcium nitride . When finely divided, it spontaneously burns in air to produce the nitride. Bulk calcium is less reactive: it quickly forms a hydration coating in moist air, but below 30% relative humidity it may be stored indefinitely at room temperature. Besides the simple oxide CaO, calcium peroxide , CaO 2 , can be made by direct oxidation of calcium metal under
NADK - Misplaced Pages Continue
2016-413: The potential difference across excitable cell membranes , protein synthesis, and bone formation. Calcium is a very ductile silvery metal (sometimes described as pale yellow) whose properties are very similar to the heavier elements in its group, strontium , barium , and radium . A calcium atom has twenty electrons, with electron configuration [Ar]4s . Like the other elements placed in group 2 of
2079-424: The 1997 observation by Skulan and DePaolo that calcium minerals are isotopically lighter than the solutions from which the minerals precipitate is the basis of analogous applications in medicine and in paleoceanography. In animals with skeletons mineralized with calcium, the calcium isotopic composition of soft tissues reflects the relative rate of formation and dissolution of skeletal mineral. In humans, changes in
2142-453: The ATP in the active site. In vitro studies with various divalent metal ions have shown that zinc and manganese are preferred over magnesium, while copper and nickel are not accepted by the enzyme at all. A proposed mechanism involves the 2' alcohol oxygen acting as a nucleophile to attack the gamma-phosphoryl of ATP, releasing ADP. NADK is highly regulated by the redox state of the cell. Whereas NAD
2205-615: The NAD coenzyme . NADP is an essential coenzyme that is reduced to NADPH primarily by the pentose phosphate pathway to provide reducing power in biosynthetic processes such as fatty acid biosynthesis and nucleotide synthesis . The structure of the NADK from the archaean Archaeoglobus fulgidus has been determined. In humans, the genes NADK and MNADK encode NAD kinases localized in cytosol and mitochondria, respectively. Similarly, yeast have both cytosolic and mitochondrial isoforms, and
2268-586: The U.S. Institute of Medicine (IOM) and the European Food Safety Authority (EFSA) set Tolerable Upper Intake Levels (ULs) for combined dietary and supplemental calcium. From the IOM, people of ages 9–18 years are not to exceed 3 g/day combined intake; for ages 19–50, not to exceed 2.5 g/day; for ages 51 and older, not to exceed 2 g/day. EFSA set the UL for all adults at 2.5 g/day, but decided
2331-567: The absence of steric hindrance , smaller group 2 cations tend to form stronger complexes, but when large polydentate macrocycles are involved the trend is reversed. Though calcium is in the same group as magnesium and organomagnesium compounds are very widely used throughout chemistry, organocalcium compounds are not similarly widespread because they are more difficult to make and more reactive, though they have recently been investigated as possible catalysts . Organocalcium compounds tend to be more similar to organoytterbium compounds due to
2394-488: The alkali metals and the divalent lanthanides europium and ytterbium , calcium metal dissolves directly in liquid ammonia to give a dark blue solution. Due to the large size of the calcium ion (Ca ), high coordination numbers are common, up to 24 in some intermetallic compounds such as CaZn 13 . Calcium is readily complexed by oxygen chelates such as EDTA and polyphosphates , which are useful in analytic chemistry and removing calcium ions from hard water . In
2457-515: The calcium isotopic composition of urine have been shown to be related to changes in bone mineral balance. When the rate of bone formation exceeds the rate of bone resorption, the Ca/ Ca ratio in soft tissue rises and vice versa. Because of this relationship, calcium isotopic measurements of urine or blood may be useful in the early detection of metabolic bone diseases like osteoporosis . A similar system exists in seawater, where Ca/ Ca tends to rise when
2520-475: The cytosolic NADPH pool to increase oxidative stress and synergizes with chemotherapy. While the role of NADK in increasing the NADPH pool appears to offer protection against apoptosis , there are also cases where NADK activity appears to potentiate cell death. Genetic studies done in human haploid cell lines indicate that knocking out NADK may protect from certain non-apoptotic stimuli. Calcium Calcium
2583-434: The divalent salts and calcium metal, because the enthalpy of formation of MX 2 is much higher than those of the hypothetical MX. This occurs because of the much greater lattice energy afforded by the more highly charged Ca cation compared to the hypothetical Ca cation. Calcium, strontium, barium, and radium are always considered to be alkaline earth metals ; the lighter beryllium and magnesium , also in group 2 of
NADK - Misplaced Pages Continue
2646-439: The element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for calcium supplementation , in the paper industry as bleaches, as components in cement and electrical insulators, and in the manufacture of soaps. On the other hand, the metal in pure form has few applications due to its high reactivity; still, in small quantities it is often used as an alloying component in steelmaking, and sometimes, as
2709-440: The essential role of NADPH in lipid and DNA biosynthesis and the hyperproliferative nature of most cancers, NADK is an attractive target for cancer therapy. Furthermore, NADPH is required for the antioxidant activities of thioredoxin reductase and glutaredoxin . Thionicotinamide and other nicotinamide analogs are potential inhibitors of NADK, and studies show that treatment of colon cancer cells with thionicotinamide suppresses
2772-399: The first and the second. Direct activation of enzymes by binding calcium is common; some other enzymes are activated by noncovalent association with direct calcium-binding enzymes. Calcium also binds to the phospholipid layer of the cell membrane , anchoring proteins associated with the cell surface. As an example of the wide range of solubility of calcium compounds, monocalcium phosphate
2835-731: The first type include limestone , dolomite , marble , chalk , and iceland spar ; aragonite beds make up the Bahamas , the Florida Keys , and the Red Sea basins. Corals , sea shells , and pearls are mostly made up of calcium carbonate. Among the other important minerals of calcium are gypsum (CaSO 4 ·2H 2 O), anhydrite (CaSO 4 ), fluorite (CaF 2 ), and apatite ([Ca 5 (PO 4 ) 3 X], X = OH, Cl, or F).gre The major producers of calcium are China (about 10000 to 12000 tonnes per year), Russia (about 6000 to 8000 tonnes per year), and
2898-415: The formation of bone by allowing and enhancing the deposition of calcium ions there, allowing rapid bone turnover without affecting bone mass or mineral content. When plasma calcium levels fall, cell surface receptors are activated and the secretion of parathyroid hormone occurs; it then proceeds to stimulate the entry of calcium into the plasma pool by taking it from targeted kidney, gut, and bone cells, with
2961-417: The information for children and adolescents was not sufficient to determine ULs. Calcium is an essential element needed in large quantities. The Ca ion acts as an electrolyte and is vital to the health of the muscular, circulatory, and digestive systems; is indispensable to the building of bone in the form of hydroxyapatite ; and supports synthesis and function of blood cells. For example, it regulates
3024-501: The most common isotope of calcium in nature is Ca, which makes up 96.941% of all natural calcium. It is produced in the silicon-burning process from fusion of alpha particles and is the heaviest stable nuclide with equal proton and neutron numbers; its occurrence is also supplemented slowly by the decay of primordial K . Adding another alpha particle leads to unstable Ti, which decays via two successive electron captures to stable Ca; this makes up 2.806% of all natural calcium and
3087-434: The neighbouring group 2 metals. It crystallises in the face-centered cubic arrangement like strontium and barium; above 443 °C (716 K), it changes to a body-centered cubic . Its density of 1.526 g/cm (at 20 °C) is the lowest in its group. Calcium is harder than lead but can be cut with a knife with effort. While calcium is a poorer conductor of electricity than copper or aluminium by volume, it
3150-525: The only element with two primordial doubly magic isotopes. The experimental lower limits for the half-lives of Ca and Ca are 5.9 × 10 years and 2.8 × 10 years respectively. Apart from the practically stable Ca, the longest lived radioisotope of calcium is Ca. It decays by electron capture to stable K with a half-life of about 10 years. Its existence in the early Solar System as an extinct radionuclide has been inferred from excesses of K: traces of Ca also still exist today, as it
3213-419: The other hand increases the compound's solubility, volatility, and kinetic stability. Natural calcium is a mixture of five stable isotopes ( Ca, Ca, Ca, Ca, and Ca) and one isotope with a half-life so long that it is for all practical purposes stable ( Ca , with a half-life of about 4.3 × 10 years). Calcium is the first (lightest) element to have six naturally occurring isotopes. By far
SECTION 50
#17328561451043276-540: The periodic table, are often included as well. Nevertheless, beryllium and magnesium differ significantly from the other members of the group in their physical and chemical behavior: they behave more like aluminium and zinc respectively and have some of the weaker metallic character of the post-transition metals , which is why the traditional definition of the term "alkaline earth metal" excludes them. Calcium metal melts at 842 °C and boils at 1494 °C; these values are higher than those for magnesium and strontium,
3339-450: The periodic table, calcium has two valence electrons in the outermost s-orbital, which are very easily lost in chemical reactions to form a dipositive ion with the stable electron configuration of a noble gas , in this case argon . Hence, calcium is almost always divalent in its compounds, which are usually ionic . Hypothetical univalent salts of calcium would be stable with respect to their elements, but not to disproportionation to
3402-473: The plaster in the tomb of Tutankhamun . The ancient Romans instead used lime mortars made by heating limestone (CaCO 3 ). The name "calcium" itself derives from the Latin word calx "lime". Vitruvius noted that the lime that resulted was lighter than the original limestone, attributing this to the boiling of the water. In 1755, Joseph Black proved that this was due to the loss of carbon dioxide , which as
3465-408: The rate of removal of Ca by mineral precipitation exceeds the input of new calcium into the ocean. In 1997, Skulan and DePaolo presented the first evidence of change in seawater Ca/ Ca over geologic time, along with a theoretical explanation of these changes. More recent papers have confirmed this observation, demonstrating that seawater Ca concentration is not constant, and that the ocean is never in
3528-407: The salt involved: calcium citrate , malate , and lactate are highly bioavailable, while the oxalate is less. Other calcium preparations include calcium carbonate , calcium citrate malate , and calcium gluconate . The intestine absorbs about one-third of calcium eaten as the free ion , and plasma calcium level is then regulated by the kidneys . Parathyroid hormone and vitamin D promote
3591-421: The similar ionic radii of Yb (102 pm) and Ca (100 pm). Most of these compounds can only be prepared at low temperatures; bulky ligands tend to favor stability. For example, calcium di cyclopentadienyl , Ca(C 5 H 5 ) 2 , must be made by directly reacting calcium metal with mercurocene or cyclopentadiene itself; replacing the C 5 H 5 ligand with the bulkier C 5 (CH 3 ) 5 ligand on
3654-500: The simplest terms, mountain-building exposes calcium-bearing rocks such as basalt and granodiorite to chemical weathering and releases Ca into surface water. These ions are transported to the ocean where they react with dissolved CO 2 to form limestone ( CaCO 3 ), which in turn settles to the sea floor where it is incorporated into new rocks. Dissolved CO 2 , along with carbonate and bicarbonate ions, are termed " dissolved inorganic carbon " (DIC). The actual reaction
3717-522: The steel and become small and spherical, improving castability, cleanliness and general mechanical properties. Calcium is also used in maintenance-free automotive batteries , in which the use of 0.1% calcium– lead alloys instead of the usual antimony –lead alloys leads to lower water loss and lower self-discharging. Due to the risk of expansion and cracking, aluminium is sometimes also incorporated into these alloys. These lead–calcium alloys are also used in casting, replacing lead–antimony alloys. Calcium
3780-587: The surficial system (atmosphere, ocean, soils and living organisms), storing it in carbonate rocks where it is likely to stay for hundreds of millions of years. The weathering of calcium from rocks thus scrubs CO 2 from the ocean and atmosphere, exerting a strong long-term effect on climate. The largest use of metallic calcium is in steelmaking , due to its strong chemical affinity for oxygen and sulfur . Its oxides and sulfides, once formed, give liquid lime aluminate and sulfide inclusions in steel which float out; on treatment, these inclusions disperse throughout
3843-473: The surrounding solution enriched in heavier isotopes at a magnitude of roughly 0.025% per atomic mass unit (amu) at room temperature. Mass-dependent differences in calcium isotope composition are conventionally expressed by the ratio of two isotopes (usually Ca/ Ca) in a sample compared to the same ratio in a standard reference material. Ca/ Ca varies by about 1- 2‰ among organisms on Earth. Calcium compounds were known for millennia, though their chemical makeup
SECTION 60
#17328561451043906-455: The yeast mitochondrial isoform accepts both NAD and NADH as substrates for phosphorylation. The reaction catalyzed by NADK is NADK phosphorylates NAD at the 2’ position of the ribose ring that carries the adenine moiety. It is highly selective for its substrates, NAD and ATP, and does not tolerate modifications either to the phosphoryl acceptor, NAD, or the pyridine moiety of the phosphoryl donor, ATP. NADK also uses metal ions to coordinate
3969-504: Was not understood until the 17th century. Lime as a building material and as plaster for statues was used as far back as around 7000 BC. The first dated lime kiln dates back to 2500 BC and was found in Khafajah , Mesopotamia . About the same time, dehydrated gypsum (CaSO 4 ·2H 2 O) was being used in the Great Pyramid of Giza . This material would later be used for
#103896