The alpha carbon in organic molecules refers to the first carbon atom that attaches to a functional group, such as a carbonyl. The second carbon atom is called the beta carbon, the system continues naming in alphabetical order with Greek letters; the nomenclature can be applied to the hydrogen atoms attached to the carbon atoms. A hydrogen atom attached to an alpha carbon atom is called an alpha-hydrogen atom, a hydrogen atom on the beta-carbon atom is a beta hydrogen atom, so on; this naming standard may not be in compliance with IUPAC nomenclature, which encourages that carbons be identified by number, not by Greek letter, but it nonetheless remains popular, in particular because it is useful in identifying the relative location of carbon atoms to other functional groups. Organic molecules with more than one functional group can be a source of confusion; the functional group responsible for the name or type of the molecule is the'reference' group for purposes of carbon-atom naming. For example, the molecules nitrostyrene and phenethylamine are similar.
However, nitrostyrene's α-carbon atom is adjacent to the phenyl group. Alpha-carbon is a term that applies to proteins and amino acids, it is the backbone carbon before the carbonyl carbon atom in the molecule. Therefore, reading along the backbone of a typical protein would give a sequence of –n– etc.. The α-carbon is; that is, the groups hanging off the chain at the α-carbon are what give amino acids their diversity. These groups give the α-carbon its stereogenic properties for every amino acid except for glycine. Therefore, the α-carbon is a stereocenter for every amino acid except glycine. Glycine does not have a β-carbon, while every other amino acid does; the α-carbon of an amino acid is significant in protein folding. When describing a protein, a chain of amino acids, one approximates the location of each amino acid as the location of its α-carbon. In general, α-carbons of adjacent amino acids in a protein are about 3.8 ångströms apart. The α-carbon is important for enol- and enolate-based carbonyl chemistry as well.
Chemical transformations affected by the conversion to either an enolate or an enol, in general, lead to the α-carbon acting as a nucleophile, for example, alkylated in the presence of primary haloalkane. An exception is in reaction with silyl chlorides and iodides, where the oxygen acts as the nucleophile to produce silyl enol ether. ^ Hackh's Chemical Dictionary, 1969, page 30. ^ Hackh's Chemical Dictionary, 1969, page 95. Media related to Alpha and beta carbon at Wikimedia Commons
Horace Raymond Huntley was an English actor who appeared in dozens of British films from the 1930s to the 1970s. He appeared in the ITV period drama Upstairs, Downstairs as the pragmatic family solicitor Sir Geoffrey Dillon. Born in Kings Norton, Worcestershire in 1904, Huntley made his stage debut at the Birmingham Repertory Theatre on 1 April 1922, in A Woman Killed with Kindness, his London debut followed at the Court Theatre on 22 February 1924, in As Far. He subsequently inherited the role of Count Dracula from Edmund Blake in Hamilton Deane's touring adaptation of Dracula, which arrived at London's Little Theatre on 14 February 1927, subsequently transferring to the larger Duke of York's Theatre; that year he was offered the chance to reprise the role on Broadway. Huntley did, appear in a US touring production of the Deane/Balderston play, covering the east coast and midwest, from 1928-30. "I have always considered the role of Count Dracula to have been an indiscretion of my youth," he recalled in 1989.
After Dracula, he made his Broadway debut at the Vanderbilt Theatre on 23 February 1931, in The Venetian Glass Nephew. On returning to the UK, his many West End appearances included The Farmer's Wife, Cornelius and the Conways, When We Are Married, They Came to a City, The Late Edwina Black, And This Was Odd, Double Image, Any Other Business, Caught Napping, Difference of Opinion, An Ideal Husband, Getting Married and Separate Tables, he starred opposite Flora Robson in the Broadway production of Black Chiffon. Cast as a supercilious bureaucrat or other authority figure, Huntley was a staple figure in British films, his many appearances including The Way Ahead, I See a Dark Stranger, Passport to Pimlico and The Dam Busters. In his years, he became well-known on television as Sir Geoffrey Dillon, the family solicitor to the Bellamys in LWT's popular 1970s drama series Upstairs, Downstairs. Huntley died in Westminster Hospital, London in 1990. In his obituary, the New York Times wrote, "During his long career the actor played judges, bank managers, churchmen and other figures of authority.
He could play them straight if necessary, but in comedy his natural dryness of delivery was exaggerated to the point where the character he was playing invited mockery as a pompous humbug." Raymond Huntley on IMDb Raymond Huntley at the Internet Broadway Database
The Ponte del Paradiso is a bridge located in Venice, Italy. Crossing the Rio del Mondo Novo, the bridge is entirely constructed out of Istrian stone bricks while the steps are paved with Trachyte, it is located within the largest of the Venetian sestieres. The bridge is known for the unique arch on its southern side serving as an entrance to the Calle del Paradiso, an alley famous for its wooden overhanging eaves. Above the bridge's southern doorway lies the Arco del Paradiso referred to as The Madonna Arch, is a sculptured Gothic-style arch depicting a Madonna at whose feet rests a friar and a couple on the canal side and inward side respectively. To either side are the arms of the Mocenigo and Foscari families commemorating a marriage between the two in 1491; the arch was in poor condition until a restoration project lead by UNESCO lasting from 1993 until 1994. Coordinates: 45.4380°N 12.3338°E / 45.4380.