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Franz Hofmeister
Franz Hofmeister (30 August 1850, in Prague – 26 July 1922, in Würzburg) was an early protein scientist, and is famous for his studies of salts that influence the solubility and conformational stability of proteins. In 1902, Hofmeister became the first to propose that polypeptides were amino acids linked by peptide bonds, although this model of protein primary structure was independently and simultaneously conceived by Emil Fischer. Early life Hofmeister's father was a doctor in Prague, where Hofmeister first began his studies, under the physiologist Karl Hugo Huppert, himself a student of Carl Lehmann. Hofmeister's ''Habilitationsschrift'' in 1879 concerned the peptic products of digestion. Hofmeister became a Professor of Pharmacology at the First Faculty of Medicine, Charles University in Prague in 1885, then eventually moved to Strasbourg in 1896. The Hofmeister series Hofmeister discovered a series of salts that have consistent effects on the solubility of proteins ...
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Salting In
Salting in refers to the effect where increasing the ionic strength of a solution increases the solubility of a solute, such as a protein. This effect tends to be observed at lower ionic strengths. Protein solubility is a complex function of physicochemical nature of the protein, pH, temperature, and the concentration of the salt used. It also depends on whether the salt is kosmotropic, whereby the salt will stabilize water. The solubility of proteins usually increases slightly in the presence of salt, referred to as "salting in". However, at high concentrations of salt, the solubility of the proteins drop sharply and proteins can precipitate out, referred to as "salting out". Anionic interactions Initial salting in at low concentrations is explained by the Debye–Huckel theory. Proteins are surrounded by the salt counterions (ions of opposite net charge) and this screening results in decreasing electrostatic free energy of the protein and increasing activity of the solvent, w ...
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German Bohemian People
German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Germanic peoples (Roman times) * German language **any of the Germanic languages * German cuisine, traditional foods of Germany People * German (given name) * German (surname) * Germán, a Spanish name Places * German (parish), Isle of Man * German, Albania, or Gërmej * German, Bulgaria * German, Iran * German, North Macedonia * German, New York, U.S. * Agios Germanos, Greece Other uses * German (mythology), a South Slavic mythological being * Germans (band), a Canadian rock band * "German" (song), a 2019 song by No Money Enterprise * ''The German'', a 2008 short film * "The Germans", an episode of ''Fawlty Towers'' * ''The German'', a nickname for Congolese rebel André Kisase Ngandu See also * Germanic (other) * G ...
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German Biochemists
German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Germanic peoples (Roman times) * German language **any of the Germanic languages * German cuisine, traditional foods of Germany People * German (given name) * German (surname) * Germán, a Spanish name Places * German (parish), Isle of Man * German, Albania, or Gërmej * German, Bulgaria * German, Iran * German, North Macedonia * German, New York, U.S. * Agios Germanos, Greece Other uses * German (mythology), a South Slavic mythological being * Germans (band), a Canadian rock band * "German" (song), a 2019 song by No Money Enterprise * ''The German'', a 2008 short film * "The Germans", an episode of ''Fawlty Towers'' * ''The German'', a nickname for Congolese rebel André Kisase Ngandu See also * Germanic (other) * G ...
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19th-century German Chemists
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under colonial rule. It was also marked by the collapse of the larg ...
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1922 Deaths
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album '' 63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album ''Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipkn ...
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1850 Births
Year 185 ( CLXXXV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Lascivius and Atilius (or, less frequently, year 938 ''Ab urbe condita''). The denomination 185 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Nobles of Britain demand that Emperor Commodus rescind all power given to Tigidius Perennis, who is eventually executed. * Publius Helvius Pertinax is made governor of Britain and quells a mutiny of the British Roman legions who wanted him to become emperor. The disgruntled usurpers go on to attempt to assassinate the governor. * Tigidius Perennis, his family and many others are executed for conspiring against Commodus. * Commodus drains Rome's treasury to put on gladiatorial spectacles and confiscates property to supp ...
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Biuret
Biuret is a chemical compound with the chemical formula . It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula , where are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. As such, it is an undesirable impurity in urea-based fertilizers. As biuret is toxic to plants, its percentage in fertilizers must be kept low. Preparation and structure The parent compound can be prepared by heating urea at 150 °C for ~6 hours until it gets slightly cloudy, then recrystallizing from water. After that, it can be recrystallized repeatedly from 2% sodium hydroxide solution and water to finally get base-free crystalline needles of the monohydrate which are free of cyanuric acid. While heating, a lot of ammonia is expelled: : Under related conditions, pyrolysis of urea affords triuret . In genera ...
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Biuret Reaction
Biuret is a chemical compound with the chemical formula . It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula , where are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. As such, it is an undesirable impurity in urea-based fertilizers. As biuret is toxic to plants, its percentage in fertilizers must be kept low. Preparation and structure The parent compound can be prepared by heating urea at 150 °C for ~6 hours until it gets slightly cloudy, then recrystallizing from water. After that, it can be recrystallized repeatedly from 2% sodium hydroxide solution and water to finally get base-free crystalline needles of the monohydrate which are free of cyanuric acid. While heating, a lot of ammonia is expelled: : Under related conditions, pyrolysis of urea affords triuret . In g ...
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Carboxylate
In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge. Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carboxylate esters'' have the general formula (or ). R and R′ are organic groups; R′ ≠ H. Synthesis Carboxylate ions can be formed by deprotonation of carboxylic acids. Such acids typically have p''K''a of less than 5, meaning that they can be deprotonated by many bases, such as sodium hydroxide or sodium bicarbonate. :RCOOH + NaOH -> RCOONa + H2O Resonance stabilization of the carboxylate ion Carboxylic acids easily dissociate into a carboxylate anion and a positively charged hydrogen ion (proton), much more readily than alcohols do (into an alkoxide ion and a proton), because the carboxylate ion is stabilized by resonance. The negative charge that is left after deprotonation of the carboxyl group is delocalized between th ...
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Trypsin
Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the digestive system of many vertebrates, where it hydrolyzes proteins. Trypsin is formed in the small intestine when its proenzyme form, the trypsinogen produced by the pancreas, is activated. Trypsin cuts peptide chains mainly at the carboxyl side of the amino acids lysine or arginine. It is used for numerous biotechnological processes. The process is commonly referred to as trypsin proteolysis or trypsinization, and proteins that have been digested/treated with trypsin are said to have been trypsinized. Trypsin was discovered in 1876 by Wilhelm Kühne and was named from the Ancient Greek word for rubbing since it was first isolated by rubbing the pancreas with glycerin. Function In the duodenum, trypsin catalyzes the hydrolysis of ...
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