Peptides are short chains of amino acid monomers linked by peptide bonds. The covalent chemical bonds are formed when the carboxyl group of one amino acid reacts with the amino group of another; the shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, etc. A polypeptide is a long and unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological oligomers and polymers, alongside nucleic acids and polysaccharides, etc. Peptides are distinguished from proteins on the basis of size, as an arbitrary benchmark can be understood to contain 50 or fewer amino acids. Proteins consist of one or more polypeptides arranged in a biologically functional way bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule, or to complex macromolecular assemblies. While aspects of the lab techniques applied to peptides versus polypeptides and proteins differ, the size boundaries that distinguish peptides from polypeptides and proteins are not absolute: long peptides such as amyloid beta have been referred to as proteins, smaller proteins like insulin have been considered peptides.
Amino acids that have been incorporated into peptides are termed "residues" due to the release of either a hydrogen ion from the amine end or a hydroxyl ion from the carboxyl end, or both, as a water molecule is released during formation of each amide bond. All peptides except cyclic peptides have an N-terminal and C-terminal residue at the end of the peptide. Many kinds of peptides are known, they have been categorized according to their sources and function. According to the Handbook of Biologically Active Peptides, some groups of peptides include plant peptides, bacterial/antibiotic peptides, fungal peptides, invertebrate peptides, amphibian/skin peptides, venom peptides, cancer/anticancer peptides, vaccine peptides, immune/inflammatory peptides, brain peptides, endocrine peptides, ingestive peptides, gastrointestinal peptides, cardiovascular peptides, renal peptides, respiratory peptides, opiate peptides, neurotrophic peptides, blood–brain peptides; some ribosomal peptides are subject to proteolysis.
These function in higher organisms, as hormones and signaling molecules. Some organisms produce peptides as antibiotics, such as microcins. Peptides have posttranslational modifications such as phosphorylation, sulfonation, palmitoylation and disulfide formation. In general, peptides are linear. More exotic manipulations do occur, such as racemization of L-amino acids to D-amino acids in platypus venom. Nonribosomal peptides are assembled by enzymes, not the ribosome. A common non-ribosomal peptide is glutathione, a component of the antioxidant defenses of most aerobic organisms. Other nonribosomal peptides are most common in unicellular organisms and fungi and are synthesized by modular enzyme complexes called nonribosomal peptide synthetases; these complexes are laid out in a similar fashion, they can contain many different modules to perform a diverse set of chemical manipulations on the developing product. These peptides are cyclic and can have complex cyclic structures, although linear nonribosomal peptides are common.
Since the system is related to the machinery for building fatty acids and polyketides, hybrid compounds are found. The presence of oxazoles or thiazoles indicates that the compound was synthesized in this fashion. Peptide fragments refer to fragments of proteins that are used to identify or quantify the source protein; these are the products of enzymatic degradation performed in the laboratory on a controlled sample, but can be forensic or paleontological samples that have been degraded by natural effects. Use of peptides received prominence in molecular biology for several reasons; the first is that peptides allow the creation of peptide antibodies in animals without the need of purifying the protein of interest. This involves synthesizing antigenic peptides of sections of the protein of interest; these will be used to make antibodies in a rabbit or mouse against the protein. Another reason is that techniques such as mass spectrometry enable the identification of proteins based on the peptide masses and sequence that result from their fragmentation.
Peptides have been used in the study of protein structure and function. For example, synthetic peptides can be used as probes to see where protein-peptide interactions occur- see the page on Protein tags. Inhibitory peptides are used in clinical research to examine the effects of peptides on the inhibition of cancer proteins and other diseases. For example, one of the most promising application is through peptides that target LHRH; these particular peptides act as an agonist, meaning that they bind to a cell in a way that regulates LHRH receptors. The process of inhibiting the cell receptors suggests that peptides could be beneficial in treating prostate cancer, but additional investigations and experiments are required before their cancer-fighting attributes can be considered definitive; the peptide families in this section are ribosomal peptides with hormonal activity. All of these peptides are synthesized by cells as longer "propeptides" or "proproteins" and truncated prior to exiting the cell.
They are released into the bloodstream. Magainin family Cecropin famil
Organic chemistry is a subdiscipline of chemistry that studies the structure and reactions of organic compounds, which contain carbon in covalent bonding. Study of structure determines their chemical formula. Study of properties includes physical and chemical properties, evaluation of chemical reactivity to understand their behavior; the study of organic reactions includes the chemical synthesis of natural products and polymers, study of individual organic molecules in the laboratory and via theoretical study. The range of chemicals studied in organic chemistry includes hydrocarbons as well as compounds based on carbon, but containing other elements oxygen, sulfur and the halogens. Organometallic chemistry is the study of compounds containing carbon–metal bonds. In addition, contemporary research focuses on organic chemistry involving other organometallics including the lanthanides, but the transition metals zinc, palladium, cobalt and chromium. Organic compounds constitute the majority of known chemicals.
The bonding patterns of carbon, with its valence of four—formal single and triple bonds, plus structures with delocalized electrons—make the array of organic compounds structurally diverse, their range of applications enormous. They form the basis of, or are constituents of, many commercial products including pharmaceuticals; the study of organic chemistry overlaps organometallic chemistry and biochemistry, but with medicinal chemistry, polymer chemistry, materials science. Before the nineteenth century, chemists believed that compounds obtained from living organisms were endowed with a vital force that distinguished them from inorganic compounds. According to the concept of vitalism, organic matter was endowed with a "vital force". During the first half of the nineteenth century, some of the first systematic studies of organic compounds were reported. Around 1816 Michel Chevreul started a study of soaps made from various alkalis, he separated the different acids. Since these were all individual compounds, he demonstrated that it was possible to make a chemical change in various fats, producing new compounds, without "vital force".
In 1828 Friedrich Wöhler produced the organic chemical urea, a constituent of urine, from inorganic starting materials, in what is now called the Wöhler synthesis. Although Wöhler himself was cautious about claiming he had disproved vitalism, this was the first time a substance thought to be organic was synthesized in the laboratory without biological starting materials; the event is now accepted as indeed disproving the doctrine of vitalism. In 1856 William Henry Perkin, while trying to manufacture quinine accidentally produced the organic dye now known as Perkin's mauve, his discovery, made known through its financial success increased interest in organic chemistry. A crucial breakthrough for organic chemistry was the concept of chemical structure, developed independently in 1858 by both Friedrich August Kekulé and Archibald Scott Couper. Both researchers suggested that tetravalent carbon atoms could link to each other to form a carbon lattice, that the detailed patterns of atomic bonding could be discerned by skillful interpretations of appropriate chemical reactions.
The era of the pharmaceutical industry began in the last decade of the 19th century when the manufacturing of acetylsalicylic acid—more referred to as aspirin—in Germany was started by Bayer. By 1910 Paul Ehrlich and his laboratory group began developing arsenic-based arsphenamine, as the first effective medicinal treatment of syphilis, thereby initiated the medical practice of chemotherapy. Ehrlich popularized the concepts of "magic bullet" drugs and of systematically improving drug therapies, his laboratory made decisive contributions to developing antiserum for diphtheria and standardizing therapeutic serums. Early examples of organic reactions and applications were found because of a combination of luck and preparation for unexpected observations; the latter half of the 19th century however witnessed systematic studies of organic compounds. The development of synthetic indigo is illustrative; the production of indigo from plant sources dropped from 19,000 tons in 1897 to 1,000 tons by 1914 thanks to the synthetic methods developed by Adolf von Baeyer.
In 2002, 17,000 tons of synthetic indigo were produced from petrochemicals. In the early part of the 20th century and enzymes were shown to be large organic molecules, petroleum was shown to be of biological origin; the multiple-step synthesis of complex organic compounds is called total synthesis. Total synthesis of complex natural compounds increased in complexity to terpineol. For example, cholesterol-related compounds have opened ways to synthesize complex human hormones and their modified derivatives. Since the start of the 20th century, complexity of total syntheses has been increased to include molecules of high complexity such as lysergic acid and vitamin B12; the discovery of petroleum and the development of the petrochemical industry spurred the development of organic chemistry. Converting individual petroleum compounds into different types of compounds by various chemical processes led to organic reactions enabling a broad range of
Inorganic chemistry deals with the synthesis and behavior of inorganic and organometallic compounds. This field covers all chemical compounds except the myriad organic compounds, which are the subjects of organic chemistry; the distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, surfactants, medications and agriculture. Many inorganic compounds are ionic compounds, consisting of cations and anions joined by ionic bonding. Examples of salts are magnesium chloride MgCl2, which consists of magnesium cations Mg2+ and chloride anions Cl−. In any salt, the proportions of the ions are such that the electric charges cancel out, so that the bulk compound is electrically neutral; the ions are described by their oxidation state and their ease of formation can be inferred from the ionization potential or from the electron affinity of the parent elements.
Important classes of inorganic compounds are the oxides, the carbonates, the sulfates, the halides. Many inorganic compounds are characterized by high melting points. Inorganic salts are poor conductors in the solid state. Other important features include their high melting ease of crystallization. Where some salts are soluble in water, others are not; the simplest inorganic reaction is double displacement when in mixing of two salts the ions are swapped without a change in oxidation state. In redox reactions one reactant, the oxidant, lowers its oxidation state and another reactant, the reductant, has its oxidation state increased; the net result is an exchange of electrons. Electron exchange can occur indirectly as well, e.g. in batteries, a key concept in electrochemistry. When one reactant contains hydrogen atoms, a reaction can take place by exchanging protons in acid-base chemistry. In a more general definition, any chemical species capable of binding to electron pairs is called a Lewis acid.
As a refinement of acid-base interactions, the HSAB theory takes into account polarizability and size of ions. Inorganic compounds are found in nature as minerals. Soil may contain iron sulfide as calcium sulfate as gypsum. Inorganic compounds are found multitasking as biomolecules: as electrolytes, in energy storage or in construction; the first important man-made inorganic compound was ammonium nitrate for soil fertilization through the Haber process. Inorganic compounds are synthesized for use as catalysts such as vanadium oxide and titanium chloride, or as reagents in organic chemistry such as lithium aluminium hydride. Subdivisions of inorganic chemistry are organometallic chemistry, cluster chemistry and bioinorganic chemistry; these fields are active areas of research in inorganic chemistry, aimed toward new catalysts and therapies. Inorganic chemistry is a practical area of science. Traditionally, the scale of a nation's economy could be evaluated by their productivity of sulfuric acid.
The top 20 inorganic chemicals manufactured in Canada, Europe, India and the US:Aluminium sulfate, Ammonium nitrate, Ammonium sulfate, Carbon black, hydrochloric acid, hydrogen peroxide, nitric acid, oxygen, phosphoric acid, sodium carbonate, sodium chlorate, sodium hydroxide, sodium silicate, sodium sulfate, sulfuric acid, titanium dioxide. The manufacturing of fertilizers is another practical application of industrial inorganic chemistry. Descriptive inorganic chemistry focuses on the classification of compounds based on their properties; the classification focuses on the position in the periodic table of the heaviest element in the compound by grouping compounds by their structural similarities. When studying inorganic compounds, one encounters parts of the different classes of inorganic chemistry. Different classifications are: Classical coordination compounds feature metals bound to "lone pairs" of electrons residing on the main group atoms of ligands such as H2O, NH3, Cl−, CN−. In modern coordination compounds all organic and inorganic compounds can be used as ligands.
The "metal" is a metal from the groups 3-13, as well as the trans-lanthanides and trans-actinides, but from a certain perspective, all chemical compounds can be described as coordination complexes. The stereochemistry of coordination complexes can be quite rich, as hinted at by Werner's separation of two enantiomers of 6+, an early demonstration that chirality is not inherent to organic compounds. A topical theme within this specialization is supramolecular coordination chemistry. Examples: −, 3+, TiCl42; these species feature elements from groups II, III, IV, V, VI, VII, 0 of the periodic table. Due to their similar reactivity, the elements in group 3 and group 12 are generally included, the lanthanides and actinides are sometimes included as well. Main group compounds have been known since the beginnings of chemistry, e.g. elemental sulfur and the distillable white phosphorus. Experiments on oxygen, O2, by Lavoisier and Priestley not only iden
Triskaidekaphobia is fear or avoidance of the number 13. It is a reason for the fear of Friday the 13th, called paraskevidekatriaphobia or friggatriskaidekaphobia; the term was used as early as in 1910 by Isador Coriat in Abnormal Psychology. From the 1890s, a number of English language sources relate the "unlucky" thirteen to an idea that at the Last Supper, the disciple who betrayed Jesus, was the 13th to sit at the table; the Bible says nothing about the order in which the Apostles sat, but there were thirteen people at the table. There is a myth that the earliest reference to thirteen being unlucky or evil is in the Babylonian Code of Hammurabi, where the thirteenth law is said to be omitted. In fact, the original Code of Hammurabi has no numeration; the translation by L. W. King, edited by Richard Hooker, omitted one article: If the seller have gone to fate, the purchaser shall recover damages in said case fivefold from the estate of the seller. Other translations of the Code of Hammurabi, for example the translation by Robert Francis Harper, include the 13th article.
Apollo 13 was launched on April 11, 1970 at 13:13:00 CST and suffered an oxygen tank explosion on April 13 at 21:07:53 CST. It returned safely to Earth on April 17. On Friday, October 13, 1307, the arrest of the Knights Templar was ordered by Philip IV of France. While the number 13 was considered unlucky, Friday the 13th was not considered unlucky at the time; the incorrect idea that their arrest was related to the phobias surrounding Friday the 13th was invented early in the 21st century and popularized by the novel The Da Vinci Code. In 1881 an influential group of New Yorkers, led by US Civil War veteran Captain William Fowler, came together to put an end to this and other superstitions, they formed a dinner cabaret club. At the first meeting, on January 13, 1881, at 8:13 p.m. thirteen people sat down to dine in Room 13 of the venue. The guests were seated among piles of spilled salt. Many "Thirteen Clubs" sprang up all over North America over the next 45 years, their activities were reported in leading newspapers, their numbers included five future US presidents, from Chester A. Arthur to Theodore Roosevelt.
Thirteen Clubs had various imitators, but they all faded due to a lack of interest. Friday the 13th mini-crash Vehicle registration plates in the Republic of Ireland are such that the first two digits represent the year of registration of the vehicle. In 2012, there were concerns among members of the Society of the Irish Motor Industry that the prospect of having "13" registered vehicles might discourage motorists from buying new cars because of superstition surrounding the number thirteen, that car sales and the motor industry would suffer as a result; the government, in consultation with SIMI, introduced a system whereby 2013 registered vehicles would have their registration plates' age identifier string modified to read "131" for vehicles registered in the first six months of 2013 and "132" for those registered in the latter six months of the year.1 Number 666 or 616. Tetraphobia, fear of the number 4. In China, Singapore, Japan and Vietnam, as well as in some other East Asian and South East Asian countries, it is not uncommon for buildings to omit floors with numbers that include the digit 4, Finnish mobile phone manufacturer Nokia's 1xxx-9xxx series of mobile phones does not include any model numbers beginning with a 4.
This originates from Classical Chinese, in which the pronunciation of the word for "four" is similar to that of the word for "death", remains so in the other countries' Sino-Xenic vocabulary. 17 is an unlucky number in Italy because in Roman numerals 17 is written XVII, which can be rearranged to "VIXI", which in Latin means "I have lived" but can be a euphemism for "I am dead." In Italy, some planes have no row 17 and some hotels have no room 17. Paraskevidekatriaphobia is the fear of Friday the 13th, considered to be a day of bad luck in a number of western cultures. In Greece and some areas of Spain and Latin America, Tuesday the 13th is considered unlucky.2 Curse of 39, a belief in some parts of Afghanistan that the number 39 is cursed or a badge of shame. In some regions 13 is considered a lucky number. For example, 13 is lucky in Italy except in some contexts, such as sitting at the dinner table. In Cantonese-speaking areas, including Hong Kong and Macau, the number 13 is considered lucky because it sounds similar to the Cantonese words meaning "sure to live".
Colgate University was started by 13 men with $13 and 13 prayers, so 13 is considered a lucky number. Friday the 13th is the luckiest day at Colgate. A number of sportspeople are known for performing successfully. On November 23, 2003, the Miami Dolphins retired the number 13 for Dan Marino, who played for the Dolphins from 1983-1999. In 1966, Portugal achieved their best-ever result at the World Cup final tournaments by finishing third, thanks to a Mozambican-born striker, who has scored nine goals at World C
Nomenclature of Organic Chemistry
Nomenclature of Organic Chemistry referred to by chemists as the Blue Book, is a collection of recommendations on organic chemical nomenclature published at irregular intervals by the International Union of Pure and Applied Chemistry. A full edition was published in 1979, an abridged and updated version of, published in 1993 as A Guide to IUPAC Nomenclature of Organic Compounds. Both of these are now out-of-print in their paper versions, but are available free of charge in electronic versions. After the release of a draft version for public comment in 2004 and the publication of several revised sections in the journal Pure and Applied Chemistry, a revised version was published in print in 2013. Nomenclature of Inorganic Chemistry Quantities and Symbols in Physical Chemistry Compendium of Chemical Terminology Compendium of Analytical Nomenclature Searchable Internet version of the 1979 and 1993 recommendations 2004 draft recommendations IUPAC Nomenclature Books Series Bibliography of translations Official corrigendum to the 1993 recommendations
Dichlorodiphenyltrichloroethane known as DDT, is a colorless and odorless crystalline chemical compound, an organochlorine developed as an insecticide, becoming infamous for its environmental impacts. It was first synthesized in 1874 by the Austrian chemist Othmar Zeidler. DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to control malaria and typhus among civilians and troops. Müller was awarded the Nobel Prize in Physiology or Medicine "for his discovery of the high efficiency of DDT as a contact poison against several arthropods" in 1948. By October 1945, DDT was available for public sale in the United States. Although it was promoted by government and industry for use as an agricultural and household pesticide, there were concerns about its use from the beginning. Opposition to DDT was focused by the 1962 publication of Rachel Carson's book Silent Spring, it cataloged environmental impacts that coincided with widespread use of DDT in agriculture in the United States, it questioned the logic of broadcasting dangerous chemicals into the environment with little prior investigation of their environmental and health effects.
The book claimed that DDT and other pesticides had been shown to cause cancer and that their agricultural use was a threat to wildlife birds. Its publication was a seminal event for the environmental movement and resulted in a large public outcry that led, in 1972, to a ban on DDT's agricultural use in the United States. A worldwide ban on agricultural use was formalized under the Stockholm Convention on Persistent Organic Pollutants, but its limited and still-controversial use in disease vector control continues, because of its effectiveness in reducing malarial infections, balanced by environmental and other health concerns. Along with the passage of the Endangered Species Act, the United States ban on DDT is a major factor in the comeback of the bald eagle and the peregrine falcon from near-extinction in the contiguous United States. DDT is similar in structure to the acaricide dicofol, it is hydrophobic and nearly insoluble in water but has good solubility in most organic solvents and oils.
DDT does not occur and is synthesised by a Friedel–Crafts hydroxyalkylation reaction between chloral and chlorobenzene, in the presence of an acidic catalyst. DDT has been marketed under trade names including Anofex, Chlorophenothane, Dinocide, Guesapon, Gyron, Neocid and Zerdane. Commercial DDT is a mixture of several closely–related compounds; the major component is p' isomer. The o,p' isomer is present in significant amounts. Dichlorodiphenyldichloroethylene and dichlorodiphenyldichloroethane make up the balance. DDE and DDD are environmental breakdown products. DDT, DDE and DDD are sometimes referred to collectively as DDX. DDT has been formulated in multiple forms, including solutions in xylene or petroleum distillates, emulsifiable concentrates, water-wettable powders, aerosols, smoke candles and charges for vaporizers and lotions. From 1950 to 1980, DDT was extensively used in agriculture – more than 40,000 tonnes each year worldwide – and it has been estimated that a total of 1.8 million tonnes have been produced globally since the 1940s.
In the United States, it was manufactured by some 15 companies, including Monsanto, Montrose Chemical Company and Velsicol Chemical Corporation. Production peaked in 1963 at 82,000 tonnes per year. More than 600,000 tonnes were applied in the US before the 1972 ban. Usage peaked in 1959 at about 36,000 tonnes. In 2009, 3,314 tonnes were produced for malaria visceral leishmaniasis. India is the only country still manufacturing DDT, is the largest consumer. China ceased production in 2007. In insects, DDT opens sodium ion channels in neurons, causing them to fire spontaneously, which leads to spasms and eventual death. Insects with certain mutations in their sodium channel gene are resistant to DDT and similar insecticides. DDT resistance is conferred by up-regulation of genes expressing cytochrome P450 in some insect species, as greater quantities of some enzymes of this group accelerate the toxin's metabolism into inactive metabolites. Genomic studies in the model genetic organism Drosophila melanogaster revealed that high level DDT resistance is polygenic, involving multiple resistance mechanisms.
DDT was first synthesized in 1874 by Othmar Zeidler under the supervision of Adolf von Baeyer. It was further described in 1929 in a dissertation by W. Bausch and in two subsequent publications in 1930; the insecticide properties of "multiple chlorinated aliphatic or fat-aromatic alcohols with at least one trichloromethane group" were described in a patent in 1934 by Wolfgang von Leuthold. DDT's insecticidal properties were not, discovered until 1939 by the Swiss scientist Paul Hermann Müller, awarded the 1948 Nobel Prize in Physiology and Medicine for his efforts. DDT is the best-known of several chlorine-containing pesticides used in the 1950s. With pyrethrum in short supply, DDT was used extensively during World War II by the Allies to control the insect vectors of typhus – nearly eliminating the disease in many parts of Europe. In the South Pacific, it was sprayed aerially for malaria and dengue fever control with spectacular effects. While DDT's chemical and insectici
Etymology is the study of the history of words. By extension, the term "the etymology" means the origin of the particular word and for place names, there is a specific term, toponymy. For Greek—with a long written history—etymologists make use of texts, texts about the language, to gather knowledge about how words were used during earlier periods and when they entered the language. Etymologists apply the methods of comparative linguistics to reconstruct information about languages that are too old for any direct information to be available. By analyzing related languages with a technique known as the comparative method, linguists can make inferences about their shared parent language and its vocabulary. In this way, word roots have been found that can be traced all the way back to the origin of, for instance, the Indo-European language family. Though etymological research grew from the philological tradition, much current etymological research is done on language families where little or no early documentation is available, such as Uralic and Austronesian.
The word etymology derives from the Greek word ἐτυμολογία, itself from ἔτυμον, meaning "true sense", the suffix -logia, denoting "the study of". In linguistics, the term etymon refers to a word or morpheme from which a word derives. For example, the Latin word candidus, which means "white", is the etymon of English candid. Etymologists apply a number of methods to study the origins of words, some of which are: Philological research. Changes in the form and meaning of the word can be traced with the aid of older texts, if such are available. Making use of dialectological data; the form or meaning of the word might show variations between dialects, which may yield clues about its earlier history. The comparative method. By a systematic comparison of related languages, etymologists may be able to detect which words derive from their common ancestor language and which were instead borrowed from another language; the study of semantic change. Etymologists must make hypotheses about changes in the meaning of particular words.
Such hypotheses are tested against the general knowledge of semantic shifts. For example, the assumption of a particular change of meaning may be substantiated by showing that the same type of change has occurred in other languages as well. Etymological theory recognizes that words originate through a limited number of basic mechanisms, the most important of which are language change, borrowing. While the origin of newly emerged words is more or less transparent, it tends to become obscured through time due to sound change or semantic change. Due to sound change, it is not obvious that the English word set is related to the word sit, it is less obvious that bless is related to blood. Semantic change may occur. For example, the English word bead meant "prayer", it acquired its modern meaning through the practice of counting the recitation of prayers by using beads. English derives from Old English, a West Germanic variety, although its current vocabulary includes words from many languages; the Old English roots may be seen in the similarity of numbers in English and German seven/sieben, eight/acht, nine/neun, ten/zehn.
Pronouns are cognate: I/mine/me and ich/mein/mich. However, language change has eroded many grammatical elements, such as the noun case system, simplified in modern English, certain elements of vocabulary, some of which are borrowed from French. Although many of the words in the English lexicon come from Romance languages, most of the common words used in English are of Germanic origin; when the Normans conquered England in 1066, they brought their Norman language with them. During the Anglo-Norman period, which united insular and continental territories, the ruling class spoke Anglo-Norman, while the peasants spoke the vernacular English of the time. Anglo-Norman was the conduit for the introduction of French into England, aided by the circulation of Langue d'oïl literature from France; this led to many paired words of English origin. For example, beef is related, through borrowing, to modern French bœuf, veal to veau, pork to porc, poultry to poulet. All these words and English, refer to the meat rather than to the animal.
Words that refer to farm animals, on the other hand, tend to be cognates of words in other Germanic languages. For example, swine/Schwein, cow/Kuh, calf/Kalb, sheep/Schaf; the variant usage has been explained by the proposition that it was the Norman rulers who ate meat and the Anglo-Saxons who farmed the animals. This explanation has been disputed. English has proved accommodating to words from many languages. Scientific terminology, for example, relies on words of Latin and Greek origin, but there are a great many non-scientific examples. Spanish has contributed many words in the southwestern United States. Examples include buckaroo, rodeo and states' names such as Colorado and Florida. Albino, lingo and coconut from Portuguese. Modern French has contributed café, naive and many more. Smorgasbord, slalom