valine (chemical compound) -- Britannica Online Encyclopedia

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It is one of several so-called essential amino acids for fowl and mammals; i.e., they cannot synthesize it and require dietary sources. 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data-options="{"vendor":"adtech","pid":1371275,"cid":225,"ifw":728,"ifh":90,"kvsource":"other","kvtopicid":"622178","kvchannel":"SCIENCE"}"></span> </div> <div id="bps-title-area" class="bps-title-area"> <h1>valine</h1> </div> <article id="toc622178main" href="/EBchecked/topic/622178/valine/622178main" class="eb-topic-article eb-content-loaded"><div class="bps-content-divider "> <div class="bps-content-type-left"></div> <div class="bps-content-type">ARTICLE</div> <div class="bps-content-type-separator"></div> <div class="bps-content-type-title"> <div class="bps-content-type-title-from">from the</div> <div class="bps-content-type-title-name">Encyclopædia Britannica</div> </div> <div class="bps-content-type-right"></div><div> <div class="bps-socialbar "> <a href="#" id="bps-socialbar-involved" title="View user assignments from our editors"><span>Get involved</span></a> <a href="#" id="bps-socialbar-share" title="Add this article to your site"><span>Share</span></a> <div id="bps-socialbar-facebook"> <iframe scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:100px; height:21px;" allowtransparency="true" src="https://web.archive.org/web/20110731083127if_/http://www.facebook.com/plugins/like.php?href=http://www.britannica.com/EBchecked/topic/622178/valine&layout=button_count&show_faces=false&width=100&action=like&font=arial&colorscheme=light&height=21"></iframe> </div> </div> </div></div><span id="1-RA" class="bps-ad-wrapper bps-advertisement-right bps-advertisement-rectangle-wrapper"><span class="bps-advertisement bps-advertisement-rectangle bps-advertisement-placeholder" data-options="{"vendor":"adtech","testVersion":"B","pid":1371285,"cid":170,"ifw":300,"ifh":250,"kvsource":"other","kvtopicid":"622178","kvchannel":"SCIENCE"}"></span></span> <p> <b><span class="srTitle"><a name="ref206357" id="ref206357" class="bps-ref-anchor"><span style="display: none;"></span></a>valine</span></b><b>,</b> an <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/20691/amino-acid" title="amino acid"><span>amino acid</span></a> obtained by <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/278896/hydrolysis" title="hydrolysis"><span>hydrolysis</span></a> of <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/479680/protein" title="proteins"><span>proteins</span></a> and first isolated by the German chemist <a name="ref206358" id="ref206358" class="bps-ref-anchor"><span style="display: none;"></span></a><a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/208392/Emil-Fischer" title="Emil Fischer"><span>Emil Fischer</span></a> (1901) from casein. It is one of several so-called essential amino acids for fowl and <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/360838/mammal" title="mammals"><span>mammals</span></a>; i.e., they cannot synthesize it and require dietary sources. It is synthesized in <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/463192/plant" title="plants"><span>plants</span></a> and microorganisms from <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/485163/pyruvic-acid" title="pyruvic acid"><span>pyruvic acid</span></a> (a product of the breakdown of <a class="bps-event-selector bps-topic-link" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/94687/carbohydrate" title="carbohydrates"><span>carbohydrates</span></a>). The chemical structure of valine is</p> <img class="inline-asset" src="https://web.archive.org/web/20110731083127im_/http://media-1.web.britannica.com/eb-media/05/124005-004-5794537A.gif" width="104" height="129"></article> <article id="toc622178rellinks" href="/EBchecked/topic/622178/valine/622178rellinks" class="eb-topic-article eb-content-loaded"><div class="bps-content-divider bps-js-required"> <div class="bps-content-type-left"></div> <div class="bps-content-type">LINKS</div> <div class="bps-content-type-separator"></div> <div class="bps-content-type-title"> <div class="bps-content-type-title-from"></div> <div class="bps-content-type-title-name">Related Articles</div> </div> <div class="bps-content-type-right"></div></div><div class="bps-advertisement bps-advertisement-rectangle bps-advertisement-placeholder bps-advertisement-right" data-options="{"vendor":"adtech","pid":1371296,"cid":170,"ifw":300,"ifh":250,"kvsource":"other","kvtopicid":"622178","kvchannel":"SCIENCE"}"></div> <p>Aspects of the topic valine are discussed in the following places at Britannica.</p> <div class="bps-index-entry-umbrella"> <h3>Assorted References</h3> <ul> <li> <strong>amino acids</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/422896/human-nutrition/250644/Amino-acids#ref869081"> human nutrition: Amino acids</a>) <p>...sufficient quantities and therefore must be taken in the diet. The essential amino acids for humans are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Conditionally indispensable amino acids include arginine, cysteine, and tyrosine, which may need to be provided under special circumstances, such as in premature infants or in people with...</p> </li> <li> <strong>maple syrup urine disease</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/363566/maple-syrup-urine-disease#ref52168"> maple syrup urine disease (pathology)</a>) <p> inherited metabolic disorder involving leucine, isoleucine, and valine (a group of branch chain amino acids). Normally, these amino acids are metabolized, step by step, by a number of enzymes, each of which is specific for each step in the metabolism of each amino acid. One of the metabolic steps consists of the decarboxylation of the <em>伪</em>-keto acids of leucine, isoleucine, and...</p> </li> <li> <strong>metabolic diseases</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/377311/metabolic-disease/250616/Organic-acidemias#ref507509"> metabolic disease (pathology): Organic acidemias</a>) <p>...tissues and fluids, especially urine. The most common of these disorders are autosomal recessive conditions that involve the metabolism of the branched-chain amino acids leucine, isoleucine, and valine. Organic acidemias share many features, including increased acid in the blood (acidemia), low blood sugar (hypoglycemia), low white blood cell count (neutropenia), poor growth, and varying...</p> </li> <li> <strong>protein</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/479680/protein/72522/Structures-of-common-amino-acids#ref593745"> protein (biochemistry): Structures of common amino acids</a>) <p>...1A). In a number of amino acids, <em>R</em> represents straight or branched carbon chains. One of these amino acids is alanine, in which <em>R</em> is the methyl group (−CH<sub class="bps-article-numbersub">3</sub>). Valine, leucine, and isoleucine, with longer <em>R</em> groups, complete the alkyl side-chain series. The alkyl side chains (<em>R</em> groups) of these amino acids are nonpolar; this means that they...</p> </li> </ul> </div> <h3>Other</h3> <div class="ac-ref-nopadding">The following is a selection of items (artistic styles or groups, constructions, events, fictional characters, organizations, publications) associated with "valine"</div> <div class="bps-index-entry-umbrella"> <ul> <li> <a title="amino acid (chemical compound)" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/20691/amino-acid" class="bps-index-entry-link bps-event-selector">amino acid (chemical compound)</a> </li> <li> <a title="valine (chemical compound)" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/622178/valine" class="bps-index-entry-link bps-event-selector">valine (chemical compound)</a> </li> </ul> </div> </article> <article id="toc622178websites" href="/EBchecked/topic/622178/valine/622178websites" class="eb-topic-article eb-content-loaded"><div class="bps-content-divider "> <div class="bps-content-type-left"></div> <div class="bps-content-type">LINKS</div> <div class="bps-content-type-separator"></div> <div class="bps-content-type-title"> <div class="bps-content-type-title-from"></div> <div class="bps-content-type-title-name">External Web Sites</div> </div> <div class="bps-content-type-right"></div></div><div class="bps-topic-web-sites-top">The topic valine is discussed at the following external Web sites.</div> <dl class="bps-topic-web-sites bps-lk-iguide"> <dt> <a title="Valine" target="_iguide" href="#">Institute of Chemistry and Biochemistry of Freie Universität Berlin - Valine</a> </dt> <dd></dd> <dt> <a title="THE AMINO ACID VALINE - BENEFITS, INFORMATION ON SUPPLEMENTS, ARTICLES, LINKS, NEWS, ADVICE" target="_iguide" href="#">Vitamins Stuff - Valine</a> </dt> <dd></dd> <dt> <a title="Valine information page. All about valine and the role it plays in your diet." target="_iguide" href="#">Sallamander Concepts - Valine</a> </dt> <dd></dd> <dt> <a title="Amino Acids - Valine" target="_iguide" href="#">The University of Arizona - Valine V</a> </dt> <dd></dd> </dl> </article> <section id="toc622178Citations" href="/EBchecked/topic/622178/valine/622178Citations" class="eb-topic-section eb-content-loaded bps-citations"> <h2>Citations</h2> <div class="bps-topic-citation"> <div class="bps-topic-citation-mla"> <a class="bps-topic-citation-style" href="/web/20110731083127/http://www.britannica.com/bps/citations" rel="nofollow"> MLA Style:</a> <div id="bps-topic-citation-mla-content" class="bps-topic-citation-text"> <p> "valine." <em>Encyclopædia Britannica. Encyclopædia Britannica Online</em>. Encyclopædia Britannica, 2011. Web. 31 Jul. 2011. <<a href="https://web.archive.org/web/20110731083127/http://www.britannica.com/EBchecked/topic/622178/valine">http://www.britannica.com/EBchecked/topic/622178/valine</a>>. </p> </div> </div> <div class="bps-topic-citation-apa"> <a class="bps-topic-citation-style" href="/web/20110731083127/http://www.britannica.com/bps/citations" rel="nofollow"> APA Style:</a> <div id="bps-topic-citation-apa-content" class="bps-topic-citation-text"> <p>valine. (2011). In <em>Encyclopædia Britannica</em>. 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class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/363566/maple-syrup-urine-disease#ref52168"> maple syrup urine disease (pathology)</a>) </li> <li> <strong>metabolic diseases</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/377311/metabolic-disease/250616/Organic-acidemias#ref507509"> metabolic disease (pathology): Organic acidemias</a>) </li> <li> <strong>protein</strong>  (<em>in</em> <a class="bps-index-entry-link bps-event-selector" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/479680/protein/72522/Structures-of-common-amino-acids#ref593745"> protein (biochemistry): Structures of common amino acids</a>) </li> </ul> </div> </div> </div>  <div class="bps-related-topics-list"> <div id="rt-content-imars" class="UI-Tab-content bps-js-required"> <h3>Other</h3><div class="ac-ref-nopadding">The following is a selection of items (artistic styles or groups, constructions, events, fictional characters, organizations, publications) associated with "valine"</div><div class="bps-index-entry-umbrella"> <ul> <li> <a title="amino acid (chemical compound)" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/20691/amino-acid" class="bps-index-entry-link bps-event-selector">amino acid (chemical compound)</a> </li> <li> <a title="valine (chemical compound)" href="/web/20110731083127/http://www.britannica.com/EBchecked/topic/622178/valine" class="bps-index-entry-link bps-event-selector">valine (chemical compound)</a> </li> </ul> </div> <h3>Quick Facts</h3><div class="ac-ref-nopadding">The following are quick facts associated with "valine"</div><div class="bps-index-entry-umbrella"> <ul> <li> <a title="Facts about valine: amino acids, as discussed in human nutrition: Amino acids:" href="https://web.archive.org/web/20110731083127/http://www.britannica.com/facts/5/869081/valine-as-discussed-in-human-nutrition" class="bps-index-entry-link bps-event-selector" target="_blank">Facts about valine: amino acids, as discussed in human nutrition: Amino acids:</a> </li> <li> <a title="Facts about valine: maple syrup urine disease, as discussed in maple syrup urine disease (pathology):" href="https://web.archive.org/web/20110731083127/http://www.britannica.com/facts/5/52168/valine-as-discussed-in-maple-syrup-urine-disease-pathology" class="bps-index-entry-link bps-event-selector" target="_blank">Facts about valine: maple syrup urine disease, as discussed in maple syrup urine disease (pathology):</a> </li> <li> <a title="Facts about valine: metabolic diseases, as discussed in metabolic disease (pathology): Organic acidemias:" href="https://web.archive.org/web/20110731083127/http://www.britannica.com/facts/5/507509/valine-as-discussed-in-metabolic-disease-pathology" 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valine (chemical compound) -- Britannica Online Encyclopedia