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Rollin Hotchkiss
Rollin Douglas Hotchkiss (1911 – December 12, 2004) was an American biochemist who helped to establish the role of DNA as the genetic material and contributed to the isolation and purification of the first antibiotics. His work on bacterial transformation helped lay the groundwork for the field of molecular genetics.Philip Siekevitz,In Memory of Rollin Hotchkiss, '' ASBC Newsletter'', February 2005. Education Hotchkiss was born in South Britain, Connecticut. The son of factory workers, he attended Yale University after scoring the highest in the nation on an achievement test. Hotchkiss earned a B.S. in chemistry in 1932, and remained at Yale for a Ph.D. in organic chemistry. After completing his doctoral work in 1935, Hotchkiss became a fellow of the Rockefeller Institute of Medical Research, where he would remain until retirement in 1982. Research career At the Rockefeller Institute, Hotchkiss initially worked as an assistant to Oswald Avery and Walter Goebel, and was enco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Material
Nucleic acids are biopolymers, macromolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is DNA. Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells and make up the genetic material. Nucleic acids are found in abundance in all living things, where they create, encode, and then store information of every living cell of every life-form on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded information is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carlsberg Laboratory
The Carlsberg Research Laboratory is a private scientific research center in Copenhagen, Denmark under the Carlsberg Group. It was founded in 1875 by J. C. Jacobsen, the founder of the Carlsberg brewery, with the purpose of advancing biochemical knowledge, especially relating to brewing. It featured a Department of Chemistry and a Department of Physiology. In 1972, the laboratory was renamed the Carlsberg Research Center and was transferred to the brewery. Overview The Carlsberg Laboratory was known for isolating '' Saccharomyces carlsbergensis'', the species of yeast responsible for lager fermentation, as well as introducing the concept of pH in acid-base chemistry. The Danish chemist Søren Peder Lauritz Sørensen introduced the concept of pH, a scale for measuring acidity and basicity of substances. While working at the Carlsberg Laboratory, he studied the effect of ion concentration on proteins, and understood the concentration of hydrogen ions was particularly import ... [...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] |
Glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (GGU, GGC, GGA, GGG). Glycine is integral to the formation of alpha-helices in secondary protein structure due to its compact form. For the same reason, it is the most abundant amino acid in collagen triple-helices. Glycine is also an inhibitory neurotransmitter – interference with its release within the spinal cord (such as during a ''Clostridium tetani'' infection) can cause spastic paralysis due to uninhibited muscle contraction. It is the only achiral proteinogenic amino acid. It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom. History and etymology Glycine was discovered in 1820 by the French chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avery–MacLeod–McCarty Experiment
The Avery–MacLeod–McCarty experiment was an experimental demonstration, reported in 1944 by Oswald Avery, Colin MacLeod, and Maclyn McCarty, that DNA is the substance that causes bacterial transformation, in an era when it had been widely believed that it was proteins that served the function of carrying genetic information (with the very word ''protein'' itself coined to indicate a belief that its function was ''primary''). It was the culmination of research in the 1930s and early 20th century at the Rockefeller Institute for Medical Research to purify and characterize the "transforming principle" responsible for the transformation phenomenon first described in Griffith's experiment of 1928: killed ''Streptococcus pneumoniae'' of the virulent strain type III-S, when injected along with living but non-virulent type II-R pneumococci, resulted in a deadly infection of type III-S pneumococci. In their paper "''Studies on the Chemical Nature of the Substance Inducing Transform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclol
The cyclol hypothesis is the now discredited first structural model of a folded, globular protein, formulated in the 1930s. It was based on the cyclol reaction of peptide bonds proposed by physicist Frederick Frank in 1936, in which two peptide groups are chemically crosslinked. These crosslinks are covalent analogs of the non-covalent hydrogen bonds between peptide groups and have been observed in rare cases, such as the ergopeptides. Based on this reaction, mathematician Dorothy Wrinch hypothesized in a series of five papers in the late 1930s a structural model of globular proteins. She postulated that, under some conditions, amino acids will spontaneously make the maximum possible number of cyclol crosslinks, resulting in cyclol molecules and cyclol fabrics. She further proposed that globular proteins have a tertiary structure corresponding to Platonic solids and semiregular polyhedra formed of cyclol fabrics with no free edges. In contrast to the cyclol reactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorothy Wrinch
Dorothy Maud Wrinch (12 September 1894 – 11 February 1976; married names Nicholson, Glaser) was a mathematician and biochemical theorist best known for her attempt to deduce protein structure using mathematical principles. She was a champion of the controversial 'cyclol' hypothesis for the structure of proteins. Career Dorothy Wrinch was born in Rosario, Argentina, the daughter of Hugh Edward Hart Wrinch, an engineer, and Ada Souter. The family returned to England and Dorothy grew up in Surbiton, near London. She attended Surbiton High School and in 1913 entered Girton College, Cambridge, Girton College, Cambridge to read mathematics. Wrinch often attended meetings of the Heretics Club run by Charles Kay Ogden, and it was through a 1914 lecture organised by Ogden that she first heard Bertrand Russell speak. She graduated in 1916 as a Wrangler (University of Cambridge), wrangler. For the academic year 1916–1917, Wrinch took the Cambridge Human science, Moral Sciences tripos a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Niemann
Carl George Niemann (July 6, 1908 – April 29, 1964) was an American biochemist who worked extensively on the chemistry and structure of proteins, publishing over 260 research papers. He is known, with Max Bergmann, for proposing the Bergmann-Niemann hypothesis that proteins consist of 288 residue polypeptides or multiples thereof with periodic sequences of amino acids, and for contributing to the downfall of the cyclol model of protein structure.Fruton (1999), p. 210-212.Anonymous (1964). Niemann was born in St. Louis and attended the University of Wisconsin–Madison. After completing his Ph.D. in biochemistry there in 1934 and staying on as research associate until 1935, Niemann took a position at the Rockefeller Institute for Medical Research, where he worked with the eminent protein chemist Max Bergmann. Niemann analyzed the amino acid content of range of proteins. Based on Niemann's tests and other published protein analyses, Bergmann and Niemann deduced that the sizes of pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Bergmann
Max Bergmann (12 February 1886 – 7 November 1944) was a Jewish-German biochemist. Together with Leonidas Zervas, the discoverer of the group, they were the first to use the carboxybenzyl protecting group for the synthesis of oligopeptides. Life and work Bergmann was born in Fürth, Bavaria, Germany on February 12, 1886, the seventh child of coal wholesalers Salomon and Rosalie Bergmann. Bergmann started studying Biology at the Ludwig Maximilian University of Munich, but lectures by Adolf von Baeyer captured his interest and eventually persuaded him to switch to Organic Chemistry. He continued his chemical studies at the Friedrich Wilhelm University of Berlin, where he was taught by Emil Fischer. After receiving his PhD under the supervision of Ignaz Bloch de.html"_;"title=":de:Ignaz_Bloch.html"_;"title="nowiki/>:de:Ignaz_Bloch">de">:de:Ignaz_Bloch.html"_;"title="nowiki/>:de:Ignaz_Bloch">de/small>_in_1911_for_his_thesis_on_Polysulfide#Organic_polysulfides.html" ;"title= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-amino Acids
D-Amino acids are amino acids where the stereogenic carbon alpha to the amino group has the D-configuration. For most naturally-occurring amino acids, this carbon has the L-configuration. D-Amino acids are occasionally found in nature as residues in proteins. They are formed from ribosomally-derived D-amino acid residues. Amino acids, as components of peptides, peptide hormones, structural and immune proteins, are the most important bioregulators involved in all life processes along with nucleic acids, carbohydrates and lipids. "Environmental D-amino acids are thought to be derived from organic diagenesis such as racemization and release from bacterial cell walls and even from microbial production." Discovery Their discovery was in the 1950s. "Auclair and Patton (1950) first reported their presence in the blood of insects and mollusks" Furthermore, they also have been identified in various mammalian tissues. The two major types of D-amino acids synthesized in and by mamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Lipmann
Fritz Albert Lipmann (; June 12, 1899 – July 24, 1986) was a German-American biochemist and a co-discoverer in 1945 of coenzyme A. For this, together with other research on coenzyme A, he was awarded the Nobel Prize in Physiology or Medicine in 1953 (shared with Hans Adolf Krebs). Early life and education Lipmann was born in Königsberg, Germany, to a Jewish family. His parents were Gertrud (Lachmanski) and Leopold Lipmann, an attorney. Lipmann studied medicine at the University of Königsberg, Berlin, and Munich, graduating in Berlin in 1924. He returned to Königsberg to study chemistry under Professor Hans Meerwein. In 1926 he joined Otto Meyerhof at the Kaiser Wilhelm Institute for Biology, Dahlem, Berlin, for his doctoral thesis. After that he followed Meyerhof to Heidelberg to the Kaiser Wilhelm Institute for Medical Research. Career From 1939 on, Lipmann lived and worked in the United States. He was a Research Associate in the Department of Biochemistry, Cornell Univer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
