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Phoebus Levene
Phoebus Aaron Theodore Levene (25 February 1869 – 6 September 1940) was a Russian born American biochemist who studied the structure and function of nucleic acids. He characterized the different forms of nucleic acid, DNA from RNA, and found that DNA contained adenine, guanine, thymine, cytosine, deoxyribose, and a phosphate group. He was born into a Litvak (Lithuanian Jewish) family as ''Fishel Rostropovich Levin'' in the town of Žagarė in Lithuania, then part of the Russian Empire, but grew up in St. Petersburg. There he studied medicine at the Imperial Military Medical Academy (M.D., 1891) and developed an interest in biochemistry. In 1893, because of anti-Semitic pogroms, he and his family emigrated to the United States and he practiced medicine in New York City. Levene enrolled at Columbia University and in his spare time conducted biochemical research, publishing papers on the chemical structure of sugars. In 1896 he was appointed as an Associate in the Pathol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoebus Levine
Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label=genitive, , ; , is one of the Twelve Olympians, Olympian deities in Ancient Greek religion, classical Greek and Ancient Roman religion, Roman religion and Greek mythology, Greek and Roman mythology. The national divinity of the Greeks, Apollo has been recognized as a god of archery, music and dance, truth and prophecy, healing and diseases, the Sun and light, poetry, and more. One of the most important and complex of the Greek gods, he is the son of Zeus and Leto, and the twin brother of Artemis, goddess of the hunt. Seen as the most beautiful god and the ideal of the ''kouros'' (ephebe, or a beardless, athletic youth), Apollo is considered to be the most Greek of all the gods. Apollo is known in Greek-influenced Etruscan mythology as ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Mayer
Adolf Eduard Mayer (9 August 184325 December 1942) was a German agricultural chemist whose work on tobacco mosaic disease played an important role in the discovery of tobacco mosaic virus and viruses in general. Mayer was born in 1843 into the family of a high school teacher in Oldenburg. His mother was a daughter of renowned German chemist Leopold Gmelin. From 1860 to 1862 he studied mathematics and chemistry at the Karlsruhe Institute of Technology. In 1862 he enrolled at the University of Heidelberg, where in 1864 he graduated summa cum laude with a Ph.D. in chemistry, physics, and mathematics. In 1879, while Mayer held the position of the director of the Agricultural Experiment Station at Wageningen in the Netherlands, he was asked by Dutch farmers to study a peculiar disease affecting the tobacco plant. Mayer published a paper in 1886 on the disease, which he named "mosaic disease of tobacco", and described its symptoms in detail. He demonstrated that the disease can be tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Emil Fischer
Hermann Emil Louis Fischer (; 9 October 1852 – 15 July 1919) was a German chemist and 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fischer projection, a symbolic way of drawing asymmetric carbon atoms. He also hypothesized lock and key mechanism of enzyme action. He never used his first given name, and was known throughout his life simply as Emil Fischer. Early years and career Fischer was born in Euskirchen, near Cologne, the son of Laurenz Fischer, a businessman, and his wife Julie Poensgen. After graduating he wished to study natural sciences, but his father compelled him to work in the family business until determining that his son was unsuitable. Fischer then attended the University of Bonn in 1871, but switched to the University of Strasbourg in 1872. He earned his doctorate in 1874 under Adolf von Baeyer with his study of phthaleins, and was appointed to a position at the university. After eight ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the List of United States cities by population density, most densely populated major city in the United States, and is more than twice as populous as second-place Los Angeles. New York City lies at the southern tip of New York (state), New York State, and constitutes the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. With over 20.1 million people in its metropolitan statistical area and 23.5 million in its combined statistical area as of 2020, New York is one of the world's most populous Megacity, megacities, and over 58 million people live within of the city. New York City is a global city, global Culture of New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pogrom
A pogrom () is a violent riot incited with the aim of massacring or expelling an ethnic or religious group, particularly Jews. The term entered the English language from Russian to describe 19th- and 20th-century attacks on Jews in the Russian Empire (mostly within the Pale of Settlement). Similar attacks against Jews which also occurred at other times and places retrospectively became known as pogroms. Sometimes the word is used to describe publicly sanctioned purgative attacks against non-Jewish groups. The characteristics of a pogrom vary widely, depending on the specific incident, at times leading to, or culminating in, massacres. Significant pogroms in the Russian Empire included the Odessa pogroms, Warsaw pogrom (1881), Kishinev pogrom (1903), Kiev pogrom (1905), and Białystok pogrom (1906). After the collapse of the Russian Empire in 1917, several pogroms occurred amidst the power struggles in Eastern Europe, including the Lwów pogrom (1918) and Kiev Pogroms (1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Empire
The Russian Empire was an empire and the final period of the Russian monarchy from 1721 to 1917, ruling across large parts of Eurasia. It succeeded the Tsardom of Russia following the Treaty of Nystad, which ended the Great Northern War. The rise of the Russian Empire coincided with the decline of neighbouring rival powers: the Swedish Empire, the Polish–Lithuanian Commonwealth, Qajar Iran, the Ottoman Empire, and Qing China. It also held colonies in North America between 1799 and 1867. Covering an area of approximately , it remains the third-largest empire in history, surpassed only by the British Empire and the Mongol Empire; it ruled over a population of 125.6 million people per the 1897 Russian census, which was the only census carried out during the entire imperial period. Owing to its geographic extent across three continents at its peak, it featured great ethnic, linguistic, religious, and economic diversity. From the 10th–17th centuries, the land ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithuanian Jews
Lithuanian Jews or Litvaks () are Jews with roots in the territory of the former Grand Duchy of Lithuania (covering present-day Lithuania, Belarus, Latvia, the northeastern Suwałki and Białystok regions of Poland, as well as adjacent areas of modern-day Russia and Ukraine). The term is sometimes used to cover all Haredi Jews who follow a " Lithuanian" ( Ashkenazi, non- Hasidic) style of life and learning, whatever their ethnic background. The area where Lithuanian Jews lived is referred to in Yiddish as , hence the Hebrew term (). No other famous Jew is more closely linked to a specifically Lithuanian city than Vilna Gaon (in Yiddish, "the genius of Vilna"). Rabbi Elijah ben Solomon Zalman (1720–1797) to give his rarely used full name, helped make Vilna (modern-day Vilnius) a world center for Talmudic learning. Chaim Grade (1910–1982) was born in Vilna, the city about which he would write. The inter-war Republic of Lithuania was home to a large and influential Jewish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxyribose
Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula H−(C=O)−(CH2)−(CHOH)3−H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of a hydroxy group. Discovered in 1929 by Phoebus Levene, deoxyribose is most notable for its presence in DNA. Since the pentose sugars arabinose and ribose only differ by the stereochemistry at C2′, 2-deoxyribose and 2-deoxyarabinose are equivalent, although the latter term is rarely used because ribose, not arabinose, is the precursor to deoxyribose. Structure Several isomers exist with the formula H−(C=O)−(CH2)−(CHOH)3−H, but in deoxyribose all the hydroxyl groups are on the same side in the Fischer projection. The term "2-deoxyribose" may refer to either of two enantiomers: the biologically important -2-deoxyribose and to the rarely encountered mirror image -2-deoxyribose.C Bernelot-Moens and B Demple (1989), ''Multiple DNA repair activities f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosine
Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, it forms three hydrogen bonds with guanine. History Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year. In 1998, cytosine was used in an early demonstration of quantum information processing when Oxford University researchers implemented the Deutsch-Jozsa algorithm on a two qubit nuclear magnetic resonance quantum computer (NMRQC). In March 2015, NASA scientists reported the formation of cytosine, along with uracil and thym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymine
Thymine () ( symbol T or Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. In RNA, thymine is replaced by the nucleobase uracil. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calf thymus glands, hence its name. Derivation As its alternate name (5-methyluracil) suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA, thymine is replaced with uracil in most cases. In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures. Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine. Thymidine can be phosphorylated with up to three phosphoric acid groups, producing dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the di- and tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanine
Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called guanosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. This unsaturated arrangement means the bicyclic molecule is planar. Properties Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. Guanine has two tautomeric forms, the major keto form (see figures) and rare enol form. It binds to cytosine through three hydrogen bonds. In cytosine, the amino group acts as the hydrogen bond donor and the C-2 carbonyl and the N-3 amine as the hydrogen-bond acceptors. Guanine has the C-6 carbonyl group that acts as the hydrogen bond acceptor, while a group at N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenine
Adenine () ( symbol A or Ade) is a nucleobase (a purine derivative). It is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The three others are guanine, cytosine and thymine. Its derivatives have a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate (ATP) and the cofactors nicotinamide adenine dinucleotide (NAD), flavin adenine dinucleotide (FAD) and Coenzyme A. It also has functions in protein synthesis and as a chemical component of DNA and RNA. The shape of adenine is complementary to either thymine in DNA or uracil in RNA. The adjacent image shows pure adenine, as an independent molecule. When connected into DNA, a covalent bond is formed between deoxyribose sugar and the bottom left nitrogen (thereby removing the existing hydrogen atom). The remaining structure is called an ''adenine residue'', as part of a larger molecule. Adenosine is ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
