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class="vector-toc-numb">2</span> <span>Essentiality in humans</span> </div> </a> <ul id="toc-Essentiality_in_humans-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-From_intermediates_of_the_citric_acid_cycle_and_other_pathways" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#From_intermediates_of_the_citric_acid_cycle_and_other_pathways"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>From intermediates of the citric acid cycle and other pathways</span> </div> </a> <ul id="toc-From_intermediates_of_the_citric_acid_cycle_and_other_pathways-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Recommended_daily_intake" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Recommended_daily_intake"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Recommended daily intake</span> </div> </a> <ul id="toc-Recommended_daily_intake-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Amino_acid_requirements_and_the_amino_acid_content_of_food" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Amino_acid_requirements_and_the_amino_acid_content_of_food"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Amino acid requirements and the amino acid content of food</span> </div> </a> <button aria-controls="toc-Amino_acid_requirements_and_the_amino_acid_content_of_food-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Amino acid requirements and the amino acid content of food subsection</span> </button> <ul id="toc-Amino_acid_requirements_and_the_amino_acid_content_of_food-sublist" class="vector-toc-list"> <li id="toc-Protein_quality" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Protein_quality"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Protein quality</span> </div> </a> <ul id="toc-Protein_quality-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Protein_per_calorie" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Protein_per_calorie"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Protein per calorie</span> </div> </a> <ul id="toc-Protein_per_calorie-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Complete_proteins_in_non-human_animals" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Complete_proteins_in_non-human_animals"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Complete proteins in non-human animals</span> </div> </a> <ul id="toc-Complete_proteins_in_non-human_animals-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Interchangeability" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interchangeability"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Interchangeability</span> </div> </a> <ul id="toc-Interchangeability-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Effects_of_deficiency" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Effects_of_deficiency"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Effects of deficiency</span> </div> </a> <ul id="toc-Effects_of_deficiency-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Essential amino acid</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 42 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-42" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">42 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%AD%D9%85%D8%B6_%D8%A3%D9%85%D9%8A%D9%86%D9%8A_%D8%B6%D8%B1%D9%88%D8%B1%D9%8A" title="حمض أميني ضروري – Arabic" lang="ar" hreflang="ar" data-title="حمض أميني ضروري" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/P%C3%AC-su_an-ki-sng" title="Pì-su an-ki-sng – Minnan" lang="nan" hreflang="nan" data-title="Pì-su an-ki-sng" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%9D%D0%B5%D0%B7%D0%B0%D0%BC%D0%B5%D0%BD%D0%BD%D1%8B%D1%8F_%D0%B0%D0%BC%D1%96%D0%BD%D0%B0%D0%BA%D1%96%D1%81%D0%BB%D0%BE%D1%82%D1%8B" title="Незаменныя амінакіслоты – Belarusian" lang="be" hreflang="be" data-title="Незаменныя амінакіслоты" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9D%D0%B5%D0%B7%D0%B0%D0%BC%D0%B5%D0%BD%D0%B8%D0%BC%D0%B8_%D0%B0%D0%BC%D0%B8%D0%BD%D0%BE%D0%BA%D0%B8%D1%81%D0%B5%D0%BB%D0%B8%D0%BD%D0%B8" title="Незаменими аминокиселини – Bulgarian" lang="bg" hreflang="bg" data-title="Незаменими аминокиселини" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Esencijalna_aminokiselina" title="Esencijalna aminokiselina – Bosnian" lang="bs" hreflang="bs" data-title="Esencijalna aminokiselina" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Amino%C3%A0cid_essencial" title="Aminoàcid essencial – Catalan" lang="ca" hreflang="ca" data-title="Aminoàcid essencial" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Esenci%C3%A1ln%C3%AD_aminokyseliny" title="Esenciální aminokyseliny – Czech" lang="cs" hreflang="cs" data-title="Esenciální aminokyseliny" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Essentiel_aminosyre" title="Essentiel aminosyre – Danish" lang="da" hreflang="da" data-title="Essentiel aminosyre" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Essentielle_Aminos%C3%A4ure" title="Essentielle Aminosäure – German" lang="de" hreflang="de" data-title="Essentielle Aminosäure" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Asendamatud_aminohapped" title="Asendamatud aminohapped – Estonian" lang="et" hreflang="et" data-title="Asendamatud aminohapped" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%92%CE%B1%CF%83%CE%B9%CE%BA%CF%8C_%CE%B1%CE%BC%CE%B9%CE%BD%CE%BF%CE%BE%CF%8D" title="Βασικό αμινοξύ – Greek" lang="el" hreflang="el" data-title="Βασικό αμινοξύ" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Amino%C3%A1cido_esencial" title="Aminoácido esencial – Spanish" lang="es" hreflang="es" data-title="Aminoácido esencial" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Enda_aminoacido" title="Enda aminoacido – Esperanto" lang="eo" hreflang="eo" data-title="Enda aminoacido" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Aminoazido_esentzial" title="Aminoazido esentzial – Basque" lang="eu" hreflang="eu" data-title="Aminoazido esentzial" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%A7%D8%B3%DB%8C%D8%AF%D9%87%D8%A7%DB%8C_%D8%A2%D9%85%DB%8C%D9%86%D9%87_%D8%B6%D8%B1%D9%88%D8%B1%DB%8C" title="اسیدهای آمینه ضروری – Persian" lang="fa" hreflang="fa" data-title="اسیدهای آمینه ضروری" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Acide_amin%C3%A9_essentiel" title="Acide aminé essentiel – French" lang="fr" hreflang="fr" data-title="Acide aminé essentiel" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Aim%C3%ADonaig%C3%A9ad_riachtanach" title="Aimíonaigéad riachtanach – Irish" lang="ga" hreflang="ga" data-title="Aimíonaigéad riachtanach" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Amino%C3%A1cido_esencial" title="Aminoácido esencial – Galician" lang="gl" hreflang="gl" data-title="Aminoácido esencial" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%ED%95%84%EC%88%98_%EC%95%84%EB%AF%B8%EB%85%B8%EC%82%B0" title="필수 아미노산 – Korean" lang="ko" hreflang="ko" data-title="필수 아미노산" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%B1%D5%B6%D6%83%D5%B8%D5%AD%D5%A1%D6%80%D5%AB%D5%B6%D5%A5%D5%AC%D5%AB_%D5%A1%D5%B4%D5%AB%D5%B6%D5%A1%D5%A9%D5%A9%D5%B8%D6%82%D5%B6%D5%A5%D6%80" title="Անփոխարինելի ամինաթթուներ – Armenian" lang="hy" hreflang="hy" data-title="Անփոխարինելի ամինաթթուներ" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Esencijalna_aminokiselina" title="Esencijalna aminokiselina – Croatian" lang="hr" hreflang="hr" data-title="Esencijalna aminokiselina" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Amminoacidi_essenziali" title="Amminoacidi essenziali – Italian" lang="it" hreflang="it" data-title="Amminoacidi essenziali" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Nepakei%C4%8Diamosios_aminor%C5%ABg%C5%A1tys" title="Nepakeičiamosios aminorūgštys – Lithuanian" lang="lt" hreflang="lt" data-title="Nepakeičiamosios aminorūgštys" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-lfn mw-list-item"><a href="https://lfn.wikipedia.org/wiki/Aminoasida_esensal" title="Aminoasida esensal – Lingua Franca Nova" lang="lfn" hreflang="lfn" data-title="Aminoasida esensal" data-language-autonym="Lingua Franca Nova" data-language-local-name="Lingua Franca Nova" class="interlanguage-link-target"><span>Lingua Franca Nova</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D2%AE%D0%BB_%D0%BE%D1%80%D0%BB%D1%83%D1%83%D0%BB%D0%B0%D1%85_%D0%B0%D0%BC%D0%B8%D0%BD_%D1%85%D2%AF%D1%87%D0%B8%D0%BB" title="Үл орлуулах амин хүчил – Mongolian" lang="mn" hreflang="mn" data-title="Үл орлуулах амин хүчил" data-language-autonym="Монгол" data-language-local-name="Mongolian" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Essentieel_aminozuur" title="Essentieel aminozuur – Dutch" lang="nl" hreflang="nl" data-title="Essentieel aminozuur" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E5%BF%85%E9%A0%88%E3%82%A2%E3%83%9F%E3%83%8E%E9%85%B8" title="必須アミノ酸 – Japanese" lang="ja" hreflang="ja" data-title="必須アミノ酸" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Aminoacid_essencial" title="Aminoacid essencial – Occitan" lang="oc" hreflang="oc" data-title="Aminoacid essencial" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Aminokwasy_egzogenne" title="Aminokwasy egzogenne – Polish" lang="pl" hreflang="pl" data-title="Aminokwasy egzogenne" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Amino%C3%A1cido_essencial" title="Aminoácido essencial – Portuguese" lang="pt" hreflang="pt" data-title="Aminoácido essencial" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Aminoacid_esen%C8%9Bial" title="Aminoacid esențial – Romanian" lang="ro" hreflang="ro" data-title="Aminoacid esențial" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9D%D0%B5%D0%B7%D0%B0%D0%BC%D0%B5%D0%BD%D0%B8%D0%BC%D1%8B%D0%B5_%D0%B0%D0%BC%D0%B8%D0%BD%D0%BE%D0%BA%D0%B8%D1%81%D0%BB%D0%BE%D1%82%D1%8B" title="Незаменимые аминокислоты – Russian" lang="ru" hreflang="ru" data-title="Незаменимые аминокислоты" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Esenci%C3%A1lna_aminokyselina" title="Esenciálna aminokyselina – Slovak" lang="sk" hreflang="sk" data-title="Esenciálna aminokyselina" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Esencialne_aminokisline" title="Esencialne aminokisline – Slovenian" lang="sl" hreflang="sl" data-title="Esencialne aminokisline" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Esencijalna_aminokiselina" title="Esencijalna aminokiselina – Serbian" lang="sr" hreflang="sr" data-title="Esencijalna aminokiselina" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Esencijalna_aminokiselina" title="Esencijalna aminokiselina – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Esencijalna aminokiselina" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/V%C3%A4ltt%C3%A4m%C3%A4t%C3%B6n_aminohappo" title="Välttämätön aminohappo – Finnish" lang="fi" hreflang="fi" data-title="Välttämätön aminohappo" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Essentiell_aminosyra" title="Essentiell aminosyra – Swedish" lang="sv" hreflang="sv" data-title="Essentiell aminosyra" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%81%E0%B8%A3%E0%B8%94%E0%B8%AD%E0%B8%B0%E0%B8%A1%E0%B8%B4%E0%B9%82%E0%B8%99%E0%B8%88%E0%B8%B3%E0%B9%80%E0%B8%9B%E0%B9%87%E0%B8%99" title="กรดอะมิโนจำเป็น – Thai" lang="th" hreflang="th" data-title="กรดอะมิโนจำเป็น" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9D%D0%B5%D0%B7%D0%B0%D0%BC%D1%96%D0%BD%D0%BD%D1%96_%D0%B0%D0%BC%D1%96%D0%BD%D0%BE%D0%BA%D0%B8%D1%81%D0%BB%D0%BE%D1%82%D0%B8" title="Незамінні амінокислоти – Ukrainian" lang="uk" hreflang="uk" data-title="Незамінні амінокислоти" 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<div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Amino acids required in diet since they can not be synthesized in body</div> <p> An <b>essential amino acid</b>, or <b>indispensable amino acid</b>, is an <a href="/wiki/Amino_acid" title="Amino acid">amino acid</a> that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life forms, the nine amino acids humans cannot synthesize are <a href="/wiki/Valine" title="Valine">valine</a>, <a href="/wiki/Isoleucine" title="Isoleucine">isoleucine</a>, <a href="/wiki/Leucine" title="Leucine">leucine</a>, <a href="/wiki/Methionine" title="Methionine">methionine</a>, <a href="/wiki/Phenylalanine" title="Phenylalanine">phenylalanine</a>, <a href="/wiki/Tryptophan" title="Tryptophan">tryptophan</a>, <a href="/wiki/Threonine" title="Threonine">threonine</a>, <a href="/wiki/Histidine" title="Histidine">histidine</a>, and <a href="/wiki/Lysine" title="Lysine">lysine</a>.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-DRI_2-0" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>Six other amino acids are considered <b>conditionally essential</b> in the human diet, meaning their synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe <a href="/wiki/Catabolism" title="Catabolism">catabolic</a> distress.<sup id="cite_ref-DRI_2-1" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> These six are <a href="/wiki/Arginine" title="Arginine">arginine</a>, <a href="/wiki/Cysteine" title="Cysteine">cysteine</a>, <a href="/wiki/Glycine" title="Glycine">glycine</a>, <a href="/wiki/Glutamine" title="Glutamine">glutamine</a>, <a href="/wiki/Proline" title="Proline">proline</a>, and <a href="/wiki/Tyrosine" title="Tyrosine">tyrosine</a>. Six amino acids are non-essential (<b>dispensable</b>) in humans, meaning they can be synthesized in sufficient quantities in the body. These six are <a href="/wiki/Alanine" title="Alanine">alanine</a>, <a href="/wiki/Aspartic_acid" title="Aspartic acid">aspartic acid</a>, <a href="/wiki/Asparagine" title="Asparagine">asparagine</a>, <a href="/wiki/Glutamic_acid" title="Glutamic acid">glutamic acid</a>, <a href="/wiki/Serine" title="Serine">serine</a>,<sup id="cite_ref-DRI_2-2" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> and <a href="/wiki/Selenocysteine" title="Selenocysteine">selenocysteine</a> (considered the 21st amino acid). <a href="/wiki/Pyrrolysine" title="Pyrrolysine">Pyrrolysine</a> (considered the 22nd amino acid),<sup id="cite_ref-LopezMohluddin_3-0" class="reference"><a href="#cite_note-LopezMohluddin-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> which is proteinogenic only in certain microorganisms, is not used by and therefore non-essential for most organisms, including humans. </p><p>The <b>limiting amino acid</b> is the essential amino acid which is furthest from meeting nutritional requirements.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> This concept is important when determining the selection, number, and amount of foods to consume because even when total protein and all other essential amino acids are satisfied if the limiting amino acid is not satisfied then the meal is considered to be nutritionally limited by that amino acid.<sup id="cite_ref-LopezMohluddin_3-1" class="reference"><a href="#cite_note-LopezMohluddin-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Overview">Overview</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=1" title="Edit section: Overview"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable"> <tbody><tr> <th>Essential </th> <th>Conditionally essential<sup id="cite_ref-FuerstStehle_5-0" class="reference"><a href="#cite_note-FuerstStehle-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-reeds_6-0" class="reference"><a href="#cite_note-reeds-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </th> <th>Non-essential </th></tr> <tr> <td><a href="/wiki/Histidine" title="Histidine">Histidine</a> (H) </td> <td><a href="/wiki/Arginine" title="Arginine">Arginine</a> (R) </td> <td><a href="/wiki/Alanine" title="Alanine">Alanine</a> (A) </td></tr> <tr> <td><a href="/wiki/Isoleucine" title="Isoleucine">Isoleucine</a> (I) </td> <td><a href="/wiki/Cysteine" title="Cysteine">Cysteine</a> (C) </td> <td><a href="/wiki/Aspartic_acid" title="Aspartic acid">Aspartic acid</a> (D) </td></tr> <tr> <td><a href="/wiki/Leucine" title="Leucine">Leucine</a> (L) </td> <td><a href="/wiki/Glutamine" title="Glutamine">Glutamine</a> (Q) </td> <td><a href="/wiki/Asparagine" title="Asparagine">Asparagine</a> (N) </td></tr> <tr> <td><a href="/wiki/Lysine" title="Lysine">Lysine</a> (K) </td> <td><a href="/wiki/Glycine" title="Glycine">Glycine</a> (G) </td> <td><a href="/wiki/Glutamic_acid" title="Glutamic acid">Glutamic acid</a> (E) </td></tr> <tr> <td><a href="/wiki/Methionine" title="Methionine">Methionine</a> (M) </td> <td><a href="/wiki/Proline" title="Proline">Proline</a> (P) </td> <td><a href="/wiki/Serine" title="Serine">Serine</a> (S) </td></tr> <tr> <td><a href="/wiki/Phenylalanine" title="Phenylalanine">Phenylalanine</a> (F) </td> <td><a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a> (Y) </td> <td><a href="/wiki/Selenocysteine" title="Selenocysteine">Selenocysteine</a> (U) </td></tr> <tr> <td><a href="/wiki/Threonine" title="Threonine">Threonine</a> (T) </td> <td><br /> </td> <td><a href="/wiki/Pyrrolysine" title="Pyrrolysine">Pyrrolysine</a>* (O) </td></tr> <tr> <td><a href="/wiki/Tryptophan" title="Tryptophan">Tryptophan</a> (W) </td> <td> </td> <td> </td></tr> <tr> <td><a href="/wiki/Valine" title="Valine">Valine</a> (V) </td> <td> </td> <td> </td></tr> </tbody></table> <p>(*) <a href="/wiki/Pyrrolysine" title="Pyrrolysine">Pyrrolysine</a>, sometimes considered the "22nd amino acid", is not used by the human body.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Essentiality_in_humans">Essentiality in humans</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=2" title="Edit section: Essentiality in humans"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Of the twenty amino acids common to all life forms (not counting <a href="/wiki/Selenocysteine" title="Selenocysteine">selenocysteine</a>), humans cannot synthesize nine: <a href="/wiki/Histidine" title="Histidine">histidine</a>, <a href="/wiki/Isoleucine" title="Isoleucine">isoleucine</a>, <a href="/wiki/Leucine" title="Leucine">leucine</a>, <a href="/wiki/Lysine" title="Lysine">lysine</a>, <a href="/wiki/Methionine" title="Methionine">methionine</a>, <a href="/wiki/Phenylalanine" title="Phenylalanine">phenylalanine</a>, <a href="/wiki/Threonine" title="Threonine">threonine</a>, <a href="/wiki/Tryptophan" title="Tryptophan">tryptophan</a> and <a href="/wiki/Valine" title="Valine">valine</a>. Additionally, the amino acids <a href="/wiki/Arginine" title="Arginine">arginine</a>, <a href="/wiki/Cysteine" title="Cysteine">cysteine</a>, <a href="/wiki/Glutamine" title="Glutamine">glutamine</a>, <a href="/wiki/Glycine" title="Glycine">glycine</a>, <a href="/wiki/Proline" title="Proline">proline</a> and <a href="/wiki/Tyrosine" title="Tyrosine">tyrosine</a> are considered <b>conditionally essential</b>,<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> which means that specific populations who do not synthesize it in adequate amounts, such as newborn infants and people with diseased livers who are unable to synthesize cysteine, must obtain one or more of these conditionally essential amino acids from their diet.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> For example, enough arginine is synthesized by the urea cycle to meet the needs of an adult but perhaps not those of a growing child. Amino acids that must be obtained from the diet are called <b>essential amino acids</b>. </p><p><a href="/wiki/Eukaryotes" class="mw-redirect" title="Eukaryotes">Eukaryotes</a> can synthesize some of the amino acids from other <a href="/wiki/Substrate_(biochemistry)" class="mw-redirect" title="Substrate (biochemistry)">substrates</a>. Consequently, only a subset of the amino acids used in protein synthesis are <a href="/wiki/Essential_nutrient" class="mw-redirect" title="Essential nutrient">essential nutrients</a>. </p> <div class="mw-heading mw-heading2"><h2 id="From_intermediates_of_the_citric_acid_cycle_and_other_pathways">From intermediates of the citric acid cycle and other pathways</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=3" title="Edit section: From intermediates of the citric acid cycle and other pathways"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Nonessential amino acids are produced in the body. The pathways for the synthesis of nonessential amino acids come from basic metabolic pathways. <a href="/wiki/Glutamate_dehydrogenase" title="Glutamate dehydrogenase">Glutamate dehydrogenase</a> catalyzes the reductive amination of <a href="/wiki/%CE%91-ketoglutarate" class="mw-redirect" title="Α-ketoglutarate">α-ketoglutarate</a> to <a href="/wiki/Glutamate" class="mw-redirect" title="Glutamate">glutamate</a>. A <a href="/wiki/Transamination" title="Transamination">transamination</a> reaction takes place in the synthesis of most amino acids. At this step, the <a href="/wiki/Chirality" title="Chirality">chirality</a> of the amino acid is established. <a href="/wiki/Alanine" title="Alanine">Alanine</a> and <a href="/wiki/Aspartate" class="mw-redirect" title="Aspartate">aspartate</a> are synthesized by the transamination of <a href="/wiki/Pyruvate" class="mw-redirect" title="Pyruvate">pyruvate</a> and <a href="/wiki/Oxaloacetate" class="mw-redirect" title="Oxaloacetate">oxaloacetate</a>, respectively. <a href="/wiki/Glutamine" title="Glutamine">Glutamine</a> is synthesized from NH<sub>4</sub><sup>+</sup> and glutamate, and <a href="/wiki/Asparagine" title="Asparagine">asparagine</a> is synthesized similarly. <a href="/wiki/Proline" title="Proline">Proline</a> and <a href="/wiki/Arginine" title="Arginine">arginine</a> are both derived from glutamate. <a href="/wiki/Serine" title="Serine">Serine</a>, formed from <a href="/wiki/3-phosphoglycerate" class="mw-redirect" title="3-phosphoglycerate">3-phosphoglycerate</a>, which comes from <a href="/wiki/Glycolysis" title="Glycolysis">glycolysis</a>, is the precursor of <a href="/wiki/Glycine" title="Glycine">glycine</a> and <a href="/wiki/Cysteine" title="Cysteine">cysteine</a>. <a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a> is synthesized by the hydroxylation of <a href="/wiki/Phenylalanine" title="Phenylalanine">phenylalanine</a>, which is an essential amino acid. </p> <div class="mw-heading mw-heading2"><h2 id="Recommended_daily_intake">Recommended daily intake</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=4" title="Edit section: Recommended daily intake"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Protein_(nutrient)" title="Protein (nutrient)">Protein (nutrient)</a></div> <p>Estimating the daily requirement for the indispensable amino acids has proven to be difficult; these numbers have undergone considerable revision over the last 20 years. The following table lists the recommended daily amounts currently in use for essential amino acids in <b>adult humans</b> (unless specified otherwise), together with their standard one-letter abbreviations. </p> <table class="wikitable"> <tbody><tr> <th rowspan="2">Essential (+ conditional) amino acid(s) </th> <th colspan="3">Daily intake in mg per kg body mass </th></tr> <tr> <th>WHO<sup id="cite_ref-WHO_11-0" class="reference"><a href="#cite_note-WHO-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </th> <th>US <a href="/wiki/National_Academy_of_Medicine" title="National Academy of Medicine">NAM</a><sup id="cite_ref-DRItext_12-0" class="reference"><a href="#cite_note-DRItext-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </th> <th>FAO (2018) young children catch-up growth<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </th></tr> <tr> <td><a href="/wiki/Histidine" title="Histidine">Histidine</a> (H) </td> <td>10 </td> <td>14 </td> <td>66 </td></tr> <tr> <td><a href="/wiki/Isoleucine" title="Isoleucine">Isoleucine</a> (I) </td> <td>20 </td> <td>19 </td> <td>95 </td></tr> <tr> <td><a href="/wiki/Leucine" title="Leucine">Leucine</a> (L) </td> <td>39 </td> <td>42 </td> <td>198 </td></tr> <tr> <td><a href="/wiki/Lysine" title="Lysine">Lysine</a> (K) </td> <td>30 </td> <td>38 </td> <td>183 </td></tr> <tr> <td><a href="/wiki/Methionine" title="Methionine">Methionine</a> (M)<br />+ <a href="/wiki/Cysteine" title="Cysteine">Cysteine</a> (C) </td> <td>10.4 + 4.1<br />(14.5 total) </td> <td>19 total </td> <td>88 </td></tr> <tr> <td><a href="/wiki/Phenylalanine" title="Phenylalanine">Phenylalanine</a> (F)<br />+ <a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a> (Y) </td> <td>25 (total) </td> <td>33 total </td> <td>177 </td></tr> <tr> <td><a href="/wiki/Threonine" title="Threonine">Threonine</a> (T) </td> <td>15 </td> <td>20 </td> <td>103 </td></tr> <tr> <td><a href="/wiki/Tryptophan" title="Tryptophan">Tryptophan</a> (W) </td> <td>4 </td> <td>5 </td> <td>29 </td></tr> <tr> <td><a href="/wiki/Valine" title="Valine">Valine</a> (V) </td> <td>26 </td> <td>24 </td> <td>130 </td></tr></tbody></table> <p>The recommended daily intakes for children aged three years and older is 10% to 20% higher than adult levels and those for infants can be as much as 150% higher in the first year of life. <a href="/wiki/Cysteine" title="Cysteine">Cysteine</a> (or sulfur-containing amino acids), <a href="/wiki/Tyrosine" title="Tyrosine">tyrosine</a> (or aromatic amino acids), and <a href="/wiki/Arginine" title="Arginine">arginine</a> are always required by infants and growing children.<sup id="cite_ref-WHO_11-1" class="reference"><a href="#cite_note-WHO-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Methionine" title="Methionine">Methionine</a> and <a href="/wiki/Cysteine" title="Cysteine">cysteine</a> are grouped together because one of them can be synthesized from the other using the enzyme <a href="/wiki/Methionine_S-methyltransferase" title="Methionine S-methyltransferase">methionine <i>S</i>-methyltransferase</a> and the catalyst <a href="/wiki/Methionine_synthase" title="Methionine synthase">methionine synthase</a>.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Phenylalanine" title="Phenylalanine">Phenylalanine</a> and <a href="/wiki/Tyrosine" title="Tyrosine">tyrosine</a> are grouped together because tyrosine can be synthesized from phenylalanine using the enzyme <a href="/wiki/Phenylalanine_hydroxylase" title="Phenylalanine hydroxylase">phenylalanine hydroxylase</a>.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Amino_acid_requirements_and_the_amino_acid_content_of_food">Amino acid requirements and the amino acid content of food</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=5" title="Edit section: Amino acid requirements and the amino acid content of food"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Historically, amino acid requirements were determined by calculating the balance between dietary <a href="/wiki/Nitrogen" title="Nitrogen">nitrogen</a> intake and nitrogen excreted in the liquid and solid wastes, because proteins represent the largest nitrogen content in a body. A positive balance occurs when more nitrogen is consumed than is excreted, which indicates that some of the nitrogen is being used by the body to build proteins. A negative nitrogen balance occurs when more nitrogen is excreted than is consumed, which indicates that there is insufficient intake for the body to maintain its health. Graduate students at the <a href="/wiki/University_of_Illinois" class="mw-redirect" title="University of Illinois">University of Illinois</a> were fed an artificial diet so that there was a slightly positive nitrogen balance. Then one amino acid was omitted and the nitrogen balance recorded. If a positive balance continued, then that amino acid was deemed not essential. If a negative balance occurred, then that amino acid was slowly restored until a slightly positive nitrogen balance stabilized and the minimum amount recorded.<sup id="cite_ref-RoseIsoleucine_17-0" class="reference"><a href="#cite_note-RoseIsoleucine-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-McGilvery1979_18-0" class="reference"><a href="#cite_note-McGilvery1979-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>A similar method was used to determine the protein content of foods. Test subjects were fed a diet containing no protein and the nitrogen losses recorded. During the first week or more there is a rapid loss of <a href="/wiki/Lability" title="Lability">labile</a> proteins. Once the nitrogen losses stabilize, this baseline is determined to be the minimum required for maintenance. Then the test subjects were fed a measured amount of the food being tested. The difference between the nitrogen in that food and the nitrogen losses above baseline was the amount the body retained to rebuild proteins. The amount of nitrogen retained divided by the total nitrogen intake is called <a href="/wiki/Net_protein_utilization" title="Net protein utilization">net protein utilization</a>. The amount of nitrogen retained divided by the (nitrogen intake minus nitrogen loss above baseline) is called <a href="/wiki/Biological_value" title="Biological value">biological value</a> and is usually given as a percentage.<sup id="cite_ref-McGilvery1979_18-1" class="reference"><a href="#cite_note-McGilvery1979-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>Modern techniques make use of <a href="/wiki/Ion_exchange_chromatography" class="mw-redirect" title="Ion exchange chromatography">ion exchange chromatography</a> to determine the actual amino acid content of foods. The <a href="/wiki/USDA" class="mw-redirect" title="USDA">USDA</a> used this technique in their own labs to determine the content of 7793 foods across 28 categories. The USDA published the final database in 2018 to the public.<sup id="cite_ref-USDAFoodData_19-0" class="reference"><a href="#cite_note-USDAFoodData-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p><p>The limiting amino acid depends on the human requirements and there are currently two sets of human requirements from authoritative sources: one published by <a href="/wiki/WHO" class="mw-redirect" title="WHO">WHO</a><sup id="cite_ref-WHO_11-2" class="reference"><a href="#cite_note-WHO-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> and the other published by <a href="/wiki/USDA" class="mw-redirect" title="USDA">USDA</a>.<sup id="cite_ref-DRItext_12-1" class="reference"><a href="#cite_note-DRItext-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p> <table class="wikitable" style="text-align:right"> <caption>This table displays the number of Items in each Category with the same limiting Essential Amino Acid <sup id="cite_ref-WHO_11-3" class="reference"><a href="#cite_note-WHO-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> <sup id="cite_ref-DRItext_12-2" class="reference"><a href="#cite_note-DRItext-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> <sup id="cite_ref-USDAFoodData_19-1" class="reference"><a href="#cite_note-USDAFoodData-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <th> </th> <th colspan="9">Based on WHO Requirements </th> <th> </th> <th colspan="9">Based on USDA Requirements </th></tr> <tr> <th>Category </th> <th class="nowrap ts-vertical-header" style=""><div style=""><style data-mw-deduplicate="TemplateStyles:r1221560606">@supports(writing-mode:vertical-rl){.mw-parser-output .ts-vertical-header{line-height:1;max-width:1em;padding:0.4em;vertical-align:bottom;width:1em}html.client-js .mw-parser-output .sortable:not(.jquery-tablesorter) .ts-vertical-header:not(.unsortable),html.client-js .mw-parser-output .ts-vertical-header.headerSort{background-position:50%.4em;padding-right:0.4em;padding-top:21px}.mw-parser-output .ts-vertical-header.is-valign-top{vertical-align:top}.mw-parser-output .ts-vertical-header.is-valign-middle{vertical-align:middle}.mw-parser-output .ts-vertical-header.is-normal{font-weight:normal}.mw-parser-output .ts-vertical-header>*{display:inline-block;transform:rotate(180deg);writing-mode:vertical-rl}@supports(writing-mode:sideways-lr){.mw-parser-output .ts-vertical-header>*{transform:none;writing-mode:sideways-lr}}}</style>Tryptophan</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Threonine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Isoleucine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Leucine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Lysine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Methionine+Cystine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Phenylalanine+Tyrosine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Valine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Histidine</div> </th> <th> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Tryptophan</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Threonine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Isoleucine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Leucine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Lysine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Methionine+Cystine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Phenylalanine+Tyrosine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Valine</div> </th> <th class="nowrap ts-vertical-header" style=""><div style=""><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1221560606">Histidine</div> </th></tr> <tr> <td>American Indian/Alaska Native Foods </td> <td>4 </td> <td>0 </td> <td>0 </td> <td>10 </td> <td>4 </td> <td>0 </td> <td>0 </td> <td>15 </td> <td>0 </td> <td> </td> <td>7 </td> <td>2 </td> <td>0 </td> <td>3 </td> <td>6 </td> <td>5 </td> <td>0 </td> <td>0 </td> <td>10 </td></tr> <tr> <td>Baby Foods </td> <td>2 </td> <td>1 </td> <td>0 </td> <td>7 </td> <td>35 </td> <td>8 </td> <td>0 </td> <td>11 </td> <td>1 </td> <td> </td> <td>5 </td> <td>1 </td> <td>0 </td> <td>5 </td> <td>34 </td> <td>13 </td> <td>0 </td> <td>0 </td> <td>7 </td></tr> <tr> <td>Baked Products </td> <td>0 </td> <td>1 </td> <td>0 </td> <td>5 </td> <td>338 </td> <td>1 </td> <td>0 </td> <td>5 </td> <td>1 </td> <td> </td> <td>0 </td> <td>1 </td> <td>0 </td> <td>0 </td> <td>339 </td> <td>2 </td> <td>0 </td> <td>0 </td> <td>9 </td></tr> <tr> <td>Beef Products </td> <td>276 </td> <td>0 </td> <td>6 </td> <td>2 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>649 </td> <td>2 </td> <td> </td> <td>289 </td> <td>1 </td> <td>0 </td> <td>176 </td> <td>6 </td> <td>300 </td> <td>0 </td> <td>159 </td> <td>4 </td></tr> <tr> <td>Beverages </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>2 </td> <td>11 </td> <td>5 </td> <td>0 </td> <td>1 </td> <td>1 </td> <td> </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>12 </td> <td>5 </td> <td>0 </td> <td>0 </td> <td>2 </td></tr> <tr> <td>Breakfast Cereals </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>1 </td> <td>40 </td> <td>1 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td> </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>1 </td> <td>40 </td> <td>1 </td> <td>0 </td> <td>0 </td> <td>0 </td></tr> <tr> <td>Cereal Grains and Pasta </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>9 </td> <td>143 </td> <td>0 </td> <td>0 </td> <td>3 </td> <td>1 </td> <td> </td> <td>2 </td> <td>1 </td> <td>0 </td> <td>4 </td> <td>148 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>1 </td></tr> <tr> <td>Dairy and Egg Products </td> <td>19 </td> <td>6 </td> <td>4 </td> <td>21 </td> <td>16 </td> <td>122 </td> <td>0 </td> <td>12 </td> <td>3 </td> <td> </td> <td>19 </td> <td>19 </td> <td>0 </td> <td>0 </td> <td>11 </td> <td>122 </td> <td>0 </td> <td>0 </td> <td>32 </td></tr> <tr> <td>Fast Foods </td> <td>4 </td> <td>3 </td> <td>0 </td> <td>9 </td> <td>39 </td> <td>8 </td> <td>0 </td> <td>62 </td> <td>1 </td> <td> </td> <td>6 </td> <td>4 </td> <td>0 </td> <td>10 </td> <td>82 </td> <td>15 </td> <td>0 </td> <td>1 </td> <td>8 </td></tr> <tr> <td>Fats and Oils </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>4 </td> <td>4 </td> <td>4 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td> </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>2 </td> <td>4 </td> <td>0 </td> <td>0 </td> <td>6 </td></tr> <tr> <td>Finfish and Shellfish Products </td> <td>3 </td> <td>3 </td> <td>0 </td> <td>15 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>228 </td> <td>0 </td> <td> </td> <td>5 </td> <td>3 </td> <td>0 </td> <td>174 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>67 </td></tr> <tr> <td>Fruits and Fruit Juices </td> <td>15 </td> <td>0 </td> <td>9 </td> <td>54 </td> <td>12 </td> <td>31 </td> <td>3 </td> <td>3 </td> <td>14 </td> <td> </td> <td>15 </td> <td>1 </td> <td>7 </td> <td>40 </td> <td>11 </td> <td>35 </td> <td>3 </td> <td>1 </td> <td>28 </td></tr> <tr> <td>Lamb </td> <td>10 </td> <td>0 </td> <td>5 </td> <td>254 </td> <td>3 </td> <td>2 </td> <td>0 </td> <td>155 </td> <td>0 </td> <td> </td> <td>10 </td> <td>0 </td> <td>2 </td> <td>207 </td> <td>9 </td> <td>112 </td> <td>0 </td> <td>2 </td> <td>87 </td></tr> <tr> <td>Legumes and Legume Products </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>26 </td> <td>154 </td> <td>0 </td> <td>22 </td> <td>0 </td> <td> </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>27 </td> <td>175 </td> <td>0 </td> <td>0 </td> <td>0 </td></tr> <tr> <td>Meals </td> <td>1 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>15 </td> <td>0 </td> <td>0 </td> <td>14 </td> <td>0 </td> <td> </td> <td>2 </td> <td>2 </td> <td>0 </td> <td>2 </td> <td>24 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>0 </td></tr> <tr> <td>Nut and Seed Products </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>24 </td> <td>96 </td> <td>8 </td> <td>0 </td> <td>0 </td> <td>0 </td> <td> </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>13 </td> <td>103 </td> <td>10 </td> <td>0 </td> <td>0 </td> <td>2 </td></tr> <tr> <td>Pork Products </td> <td>11 </td> <td>0 </td> <td>1 </td> <td>54 </td> <td>0 </td> <td>2 </td> <td>0 </td> <td>249 </td> <td>0 </td> <td> </td> <td>20 </td> <td>0 </td> <td>0 </td> <td>197 </td> <td>0 </td> <td>73 </td> <td>0 </td> <td>15 </td> <td>12 </td></tr> <tr> <td>Poultry Products </td> <td>6 </td> <td>12 </td> <td>6 </td> <td>58 </td> <td>1 </td> <td>0 </td> <td>0 </td> <td>287 </td> <td>0 </td> <td> </td> <td>36 </td> <td>22 </td> <td>0 </td> <td>167 </td> <td>5 </td> <td>8 </td> <td>0 </td> <td>99 </td> <td>33 </td></tr> <tr> <td>Restaurant Foods </td> <td>0 </td> <td>9 </td> <td>3 </td> <td>14 </td> <td>24 </td> <td>3 </td> <td>0 </td> <td>41 </td> <td>1 </td> <td> </td> <td>1 </td> <td>25 </td> <td>0 </td> <td>9 </td> <td>33 </td> <td>12 </td> <td>0 </td> <td>0 </td> <td>15 </td></tr> <tr> <td>Sausages and Luncheon Meats </td> <td>5 </td> <td>0 </td> <td>1 </td> <td>31 </td> <td>0 </td> <td>2 </td> <td>0 </td> <td>78 </td> <td>0 </td> <td> </td> <td>14 </td> <td>11 </td> <td>1 </td> <td>68 </td> <td>1 </td> <td>11 </td> <td>0 </td> <td>4 </td> <td>7 </td></tr> <tr> <td>Snacks </td> <td>2 </td> <td>0 </td> <td>0 </td> <td>6 </td> <td>83 </td> <td>6 </td> <td>0 </td> <td>4 </td> <td>1 </td> <td> </td> <td>2 </td> <td>1 </td> <td>0 </td> <td>6 </td> <td>81 </td> <td>9 </td> <td>0 </td> <td>0 </td> <td>3 </td></tr> <tr> <td>Soups </td> <td>0 </td> <td>0 </td> <td>2 </td> <td>7 </td> <td>10 </td> <td>28 </td> <td>0 </td> <td>7 </td> <td>0 </td> <td> </td> <td>0 </td> <td>0 </td> <td>0 </td> <td>1 </td> <td>21 </td> <td>31 </td> <td>0 </td> <td>0 </td> <td>1 </td></tr> <tr> <td>Spices and Herbs </td> <td>3 </td> <td>0 </td> <td>0 </td> <td>6 </td> <td>11 </td> <td>3 </td> <td>0 </td> <td>1 </td> <td>1 </td> <td> </td> <td>3 </td> <td>2 </td> <td>0 </td> <td>3 </td> <td>12 </td> <td>4 </td> <td>0 </td> <td>0 </td> <td>1 </td></tr> <tr> <td>Sweets </td> <td>0 </td> <td>1 </td> <td>0 </td> <td>3 </td> <td>17 </td> <td>47 </td> <td>0 </td> <td>1 </td> <td>2 </td> <td> </td> <td>0 </td> <td>1 </td> <td>0 </td> <td>1 </td> <td>17 </td> <td>47 </td> <td>0 </td> <td>0 </td> <td>5 </td></tr> <tr> <td>Vegetables and Vegetable Products </td> <td>7 </td> <td>0 </td> <td>8 </td> <td>238 </td> <td>114 </td> <td>199 </td> <td>0 </td> <td>18 </td> <td>19 </td> <td> </td> <td>13 </td> <td>28 </td> <td>0 </td> <td>112 </td> <td>144 </td> <td>246 </td> <td>0 </td> <td>2 </td> <td>58 </td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Protein_quality">Protein quality</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=6" title="Edit section: Protein quality"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Protein_quality" title="Protein quality">Protein quality</a></div> <p>Various attempts have been made to express the "quality" or "value" of various kinds of protein. Measures include the <a href="/wiki/Biological_value" title="Biological value">biological value</a>, <a href="/wiki/Net_protein_utilization" title="Net protein utilization">net protein utilization</a>, <a href="/wiki/Protein_efficiency_ratio" title="Protein efficiency ratio">protein efficiency ratio</a>, <a href="/wiki/Protein_digestibility_corrected_amino_acid_score" title="Protein digestibility corrected amino acid score">protein digestibility corrected amino acid score</a> and the <a href="/wiki/Complete_protein" title="Complete protein">complete proteins</a> concept. These concepts are important in the <a href="/wiki/Animal_husbandry" title="Animal husbandry">livestock industry</a>, because the relative lack of one or more of the essential amino acids in <a href="/wiki/Fodder" title="Fodder">animal feeds</a> would have a limiting effect on growth and thus on <a href="/wiki/Feed_conversion_ratio" title="Feed conversion ratio">feed conversion ratio</a>. Thus, various feedstuffs may be fed in combination to increase net protein utilization, or a <a href="/wiki/Dietary_supplement" title="Dietary supplement">supplement</a> of an individual amino acid (methionine, lysine, threonine, or tryptophan) can be added to the feed. </p> <div class="mw-heading mw-heading3"><h3 id="Protein_per_calorie">Protein per calorie</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=7" title="Edit section: Protein per calorie"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Protein content in foods is often measured in protein per serving rather than protein per calorie. For instance, the USDA lists 6 grams of protein per large whole egg (a 50-gram serving) rather than 84 mg of protein per calorie (71 calories total).<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> For comparison, there are 2.8 grams of protein in a serving of raw broccoli (100 grams) or 82 mg of protein per calorie (34 calories total), or the <a href="/wiki/Daily_Value" class="mw-redirect" title="Daily Value">Daily Value</a> of 47.67g of protein after eating 1,690g of raw broccoli a day at 574 cal.<sup id="cite_ref-Broccoli_21-0" class="reference"><a href="#cite_note-Broccoli-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> An egg contains 12.5g of protein per 100g, but 4 mg more protein per calorie, or the protein DV after 381g of egg, which is 545 cal.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> The ratio of essential amino acids (the quality of protein) is not taken into account, one would actually need to eat more than 3 kg of broccoli a day to have a healthy protein profile, and almost 6 kg to get enough calories.<sup id="cite_ref-Broccoli_21-1" class="reference"><a href="#cite_note-Broccoli-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> It is recommended that adult humans obtain between 10–35% of their 2000 calories a day as protein.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Complete_proteins_in_non-human_animals">Complete proteins in non-human animals</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=8" title="Edit section: Complete proteins in non-human animals"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Scientists had known since the early 20th century that rats could not survive on a diet whose only protein source was <a href="/wiki/Zein" title="Zein">zein</a>, which comes from <a href="/wiki/Maize" title="Maize">maize</a> (corn), but recovered if they were fed <a href="/wiki/Casein" title="Casein">casein</a> from cow's milk. This led <a href="/wiki/William_Cumming_Rose" title="William Cumming Rose">William Cumming Rose</a> to the discovery of the essential amino acid <a href="/wiki/Threonine" title="Threonine">threonine</a>.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> Through manipulation of rodent diets, Rose was able to show that ten amino acids are essential for rats: <a href="/wiki/Lysine" title="Lysine">lysine</a>, <a href="/wiki/Tryptophan" title="Tryptophan">tryptophan</a>, <a href="/wiki/Histidine" title="Histidine">histidine</a>, <a href="/wiki/Phenylalanine" title="Phenylalanine">phenylalanine</a>, <a href="/wiki/Leucine" title="Leucine">leucine</a>, <a href="/wiki/Isoleucine" title="Isoleucine">isoleucine</a>, <a href="/wiki/Methionine" title="Methionine">methionine</a>, <a href="/wiki/Valine" title="Valine">valine</a>, and <a href="/wiki/Arginine" title="Arginine">arginine</a>, in addition to threonine. Rose's later work showed that eight amino acids are essential for adult human beings, with histidine also being essential for infants. Longer-term studies established histidine as also essential for adult humans.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Interchangeability">Interchangeability</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=9" title="Edit section: Interchangeability"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The distinction between essential and non-essential amino acids is somewhat unclear, as some amino acids can be produced from others. The <a href="/wiki/Sulfur" title="Sulfur">sulfur</a>-containing amino acids, <a href="/wiki/Methionine" title="Methionine">methionine</a> and <a href="/wiki/Homocysteine" title="Homocysteine">homocysteine</a>, can be converted into each other but neither can be synthesized <i>de novo</i> in humans. Likewise, cysteine can be made from homocysteine but cannot be synthesized on its own. So, for convenience, sulfur-containing amino acids are sometimes considered a single pool of nutritionally equivalent amino acids as are the <a href="/wiki/Aromatic" class="mw-redirect" title="Aromatic">aromatic</a> amino acid pair, <a href="/wiki/Phenylalanine" title="Phenylalanine">phenylalanine</a> and <a href="/wiki/Tyrosine" title="Tyrosine">tyrosine</a>. Likewise <a href="/wiki/Arginine" title="Arginine">arginine</a>, <a href="/wiki/Ornithine" title="Ornithine">ornithine</a>, and <a href="/wiki/Citrulline" title="Citrulline">citrulline</a>, which are interconvertible by the <a href="/wiki/Urea_cycle" title="Urea cycle">urea cycle</a>, are considered a single group.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (July 2014)">citation needed</span></a></i>]</sup> </p> <div class="mw-heading mw-heading2"><h2 id="Effects_of_deficiency">Effects of deficiency</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=10" title="Edit section: Effects of deficiency"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Protein-energy_malnutrition" class="mw-redirect" title="Protein-energy malnutrition">Protein-energy malnutrition</a></div> <p>If one of the essential amino acids is not available in the required quantities, protein synthesis will be inhibited, irrespective of the availability of the other amino acids.<sup id="cite_ref-DRI_2-3" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> Protein deficiency has been shown to affect all of the body's organs and many of its systems, for example affecting brain development in infants and young children; inhibiting upkeep of the immune system, increasing risk of infection; affecting gut <a href="/wiki/Mucosal" class="mw-redirect" title="Mucosal">mucosal</a> function and permeability, thereby reducing absorption and increasing vulnerability to <a href="/wiki/Systemic_disease" title="Systemic disease">systemic disease</a>; and impacting kidney function.<sup id="cite_ref-DRI_2-4" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> The physical signs of protein deficiency include <a href="/wiki/Edema" title="Edema">edema</a>, <a href="/wiki/Failure_to_thrive" title="Failure to thrive">failure to thrive</a> in infants and children, poor musculature, dull skin, and thin and fragile hair. Biochemical changes reflecting protein deficiency include low <a href="/wiki/Serum_albumin" title="Serum albumin">serum albumin</a> and low <a href="/wiki/Serum_transferrin" class="mw-redirect" title="Serum transferrin">serum transferrin</a>.<sup id="cite_ref-DRI_2-5" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>The amino acids that are essential in the human diet were established in a series of experiments led by <a href="/wiki/William_Cumming_Rose" title="William Cumming Rose">William Cumming Rose</a>. The experiments involved elemental diets to healthy male graduate students. These diets consisted of <a href="/wiki/Corn_starch" title="Corn starch">corn starch</a>, <a href="/wiki/Sucrose" title="Sucrose">sucrose</a>, <a href="/wiki/Butterfat" title="Butterfat">butterfat</a> without protein, <a href="/wiki/Corn_oil" title="Corn oil">corn oil</a>, inorganic salts, the known <a href="/wiki/Vitamin" title="Vitamin">vitamins</a>, a large brown "candy" made of liver extract flavored with <a href="/wiki/Peppermint_oil" class="mw-redirect" title="Peppermint oil">peppermint oil</a> (to supply any unknown vitamins), and mixtures of highly purified individual amino acids. The main outcome measure was <a href="/wiki/Nitrogen_balance" title="Nitrogen balance">nitrogen balance</a>. Rose noted that the symptoms of nervousness, exhaustion, and dizziness were encountered to a greater or lesser extent whenever human subjects were deprived of an essential amino acid.<sup id="cite_ref-RoseIsoleucine_17-1" class="reference"><a href="#cite_note-RoseIsoleucine-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> </p><p>Essential amino <a href="/wiki/Acid" title="Acid">acid</a> deficiency should be distinguished from <a href="/wiki/Protein-energy_malnutrition" class="mw-redirect" title="Protein-energy malnutrition">protein-energy malnutrition</a>, which can manifest as <a href="/wiki/Marasmus" title="Marasmus">marasmus</a> or <a href="/wiki/Kwashiorkor" title="Kwashiorkor">kwashiorkor</a>. <a href="/wiki/Kwashiorkor" title="Kwashiorkor">Kwashiorkor</a> was once attributed to pure protein deficiency in individuals who were consuming enough <a href="/wiki/Calorie" title="Calorie">calories</a> ("sugar baby syndrome"). However, this theory has been challenged by the finding that there is no difference in the diets of children developing <a href="/wiki/Marasmus" title="Marasmus">marasmus</a> as opposed to kwashiorkor.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> Still, for instance in <a href="/wiki/Dietary_Reference_Intake" title="Dietary Reference Intake">Dietary Reference Intakes</a> (DRI) maintained by the <a href="/wiki/USDA" class="mw-redirect" title="USDA">USDA</a>, lack of one or more of the essential amino acids is described as <a href="/wiki/Protein-energy_malnutrition" class="mw-redirect" title="Protein-energy malnutrition">protein-energy malnutrition</a>.<sup id="cite_ref-DRI_2-6" class="reference"><a href="#cite_note-DRI-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=11" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Essential_fatty_acid" title="Essential fatty acid">Essential fatty acid</a></li> <li><a href="/wiki/Essential_genes" class="mw-redirect" title="Essential genes">Essential genes</a></li> <li><a href="/wiki/List_of_standard_amino_acids" class="mw-redirect" title="List of standard amino acids">List of standard amino acids</a></li> <li><a href="/wiki/Low-protein_diet" title="Low-protein diet">Low-protein diet</a>, <a href="/wiki/High-protein_diet" title="High-protein diet">High-protein diet</a></li> <li><a href="/wiki/Orthomolecular_medicine" title="Orthomolecular medicine">Orthomolecular medicine</a></li> <li><a href="/wiki/Ketogenic_amino_acid" title="Ketogenic amino acid">Ketogenic amino acid</a></li> <li><a href="/wiki/Glucogenic_amino_acid" title="Glucogenic amino acid">Glucogenic amino acid</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=12" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output 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The role of threonine and histidine"</a>. <i>The Journal of Biological Chemistry</i>. <b>188</b> (1): 49–58. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1016%2FS0021-9258%2818%2956144-5">10.1016/S0021-9258(18)56144-5</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/14814112">14814112</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Journal+of+Biological+Chemistry&rft.atitle=The+amino+acid+requirements+of+man.+II.+The+role+of+threonine+and+histidine&rft.volume=188&rft.issue=1&rft.pages=49-58&rft.date=1951&rft_id=info%3Adoi%2F10.1016%2FS0021-9258%2818%2956144-5&rft_id=info%3Apmid%2F14814112&rft.aulast=Rose&rft.aufirst=WC&rft.au=Haines%2C+WJ&rft.au=Warner%2C+DT&rft.au=Johnson%2C+JE&rft_id=https%3A%2F%2Fdoi.org%2F10.1016%252FS0021-9258%252818%252956144-5&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEssential+amino+acid" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKoppleSwendseid1975" class="citation journal cs1">Kopple JD, Swendseid ME (May 1975). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC301830">"Evidence that histidine is an essential amino acid in normal and chronically uremic man"</a>. <i>J Clin Invest</i>. <b>55</b> (5): 881–891. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1172%2FJCI108016">10.1172/JCI108016</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC301830">301830</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/1123426">1123426</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=J+Clin+Invest&rft.atitle=Evidence+that+histidine+is+an+essential+amino+acid+in+normal+and+chronically+uremic+man.&rft.volume=55&rft.issue=5&rft.pages=881-891&rft.date=1975-05&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC301830%23id-name%3DPMC&rft_id=info%3Apmid%2F1123426&rft_id=info%3Adoi%2F10.1172%2FJCI108016&rft.aulast=Kopple&rft.aufirst=JD&rft.au=Swendseid%2C+ME&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC301830&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEssential+amino+acid" class="Z3988"></span></span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAhmedRahmanCravioto2009" class="citation journal cs1">Ahmed T, Rahman S, Cravioto A (2009). "Oedematous malnutrition". <i>The Indian Journal of Medical Research</i>. <b>130</b> (5): 651–4. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/20090122">20090122</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Indian+Journal+of+Medical+Research&rft.atitle=Oedematous+malnutrition&rft.volume=130&rft.issue=5&rft.pages=651-4&rft.date=2009&rft_id=info%3Apmid%2F20090122&rft.aulast=Ahmed&rft.aufirst=T&rft.au=Rahman%2C+S&rft.au=Cravioto%2C+A&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEssential+amino+acid" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Essential_amino_acid&action=edit&section=13" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Essential_amino_acids" class="extiw" title="commons:Category:Essential amino acids">Essential amino acids</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="http://www.veganhealth.org/articles/protein">Amino acid content of some vegetarian foods</a> at veganhealth.org.</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20050319163510/http://www.dasc.vt.edu/extension/nutritioncc/9729.html">Amino Acid Profiles of Some Common Feeds</a> at <a href="/wiki/Virginia_Tech" title="Virginia Tech">Virginia Tech</a>.</li> <li><a rel="nofollow" class="external text" href="http://micro.magnet.fsu.edu/aminoacids/index.html">Molecular Expressions: The Amino Acid Collection</a> at <a href="/wiki/Florida_State_University" title="Florida State University">Florida State University</a>. Features detailed information and crystal photographs of each amino acid.</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120202075048/http://foodwiki.com/vprotein">vProtein</a>, an online software tool to analyze the essential amino acid profiles of single and pairs of plant based foods based on human requirements.</li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output 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href="/wiki/File:L-amino_acid_any.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0e/L-amino_acid_any.png/182px-L-amino_acid_any.png" decoding="async" width="182" height="160" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0e/L-amino_acid_any.png/273px-L-amino_acid_any.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0e/L-amino_acid_any.png/364px-L-amino_acid_any.png 2x" data-file-width="728" data-file-height="640" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">By properties</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Aliphatic_compound" title="Aliphatic compound">Aliphatic</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Branched-chain_amino_acid" title="Branched-chain amino acid">Branched-chain amino acids</a> (<a href="/wiki/Valine" title="Valine">Valine</a></li> <li><a href="/wiki/Isoleucine" title="Isoleucine">Isoleucine</a></li> <li><a href="/wiki/Leucine" title="Leucine">Leucine</a>)</li> <li><a href="/wiki/Methionine" title="Methionine">Methionine</a></li> <li><a href="/wiki/Alanine" title="Alanine">Alanine</a></li> <li><a href="/wiki/Proline" title="Proline">Proline</a></li> <li><a href="/wiki/Glycine" title="Glycine">Glycine</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Aromatic_amino_acid" title="Aromatic amino acid">Aromatic</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Histidine" title="Histidine">Histidine</a></li> <li><a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a></li> <li><a href="/wiki/Tryptophan" title="Tryptophan">Tryptophan</a></li> <li><a href="/wiki/Phenylalanine" title="Phenylalanine">Phenylalanine</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Chemical_polarity" title="Chemical polarity">Polar</a>, uncharged</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Asparagine" title="Asparagine">Asparagine</a></li> <li><a href="/wiki/Glutamine" title="Glutamine">Glutamine</a></li> <li><a href="/wiki/Serine" title="Serine">Serine</a></li> <li><a href="/wiki/Threonine" title="Threonine">Threonine</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Positive charge (p<i>K</i><sub>a</sub>)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lysine" title="Lysine">Lysine</a> (≈10.8)</li> <li><a href="/wiki/Arginine" title="Arginine">Arginine</a> (≈12.5)</li> <li><a href="/wiki/Histidine" title="Histidine">Histidine</a> (≈6.1)</li> <li><a href="/wiki/Pyrrolysine" title="Pyrrolysine">Pyrrolysine</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Negative charge (p<i>K</i><sub>a</sub>)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Aspartic_acid" title="Aspartic acid">Aspartic acid</a> (≈3.9)</li> <li><a href="/wiki/Glutamic_acid" title="Glutamic acid">Glutamic acid</a> (≈4.1)</li> <li><a href="/wiki/Selenocysteine" title="Selenocysteine">Selenocysteine</a> (≈5.4)</li> <li><a href="/wiki/Cysteine" title="Cysteine">Cysteine</a> (≈8.3)</li> <li><a href="/wiki/Tyrosine" title="Tyrosine">Tyrosine</a> (≈10.1)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="3"><div><div class="hlist" style="font-size:88%;"> <ul><li><b><a href="/wiki/Amino_acids" class="mw-redirect" title="Amino acids">Amino acids</a> types</b>: <a href="/wiki/Template:Encoded_amino_acids" class="mw-redirect" title="Template:Encoded amino acids">Encoded (proteins)</a></li> <li><a href="/wiki/Essential_amino_acids" class="mw-redirect" title="Essential amino acids">Essential</a></li> <li><a href="/wiki/Template:Non-proteinogenic_amino_acids" title="Template:Non-proteinogenic amino acids">Non-proteinogenic</a></li> <li><a href="/wiki/Ketogenic_amino_acids" class="mw-redirect" title="Ketogenic amino acids">Ketogenic</a></li> <li><a href="/wiki/Glucogenic_amino_acids" class="mw-redirect" title="Glucogenic amino acids">Glucogenic</a></li> <li><a href="/wiki/Secondary_amino_acid" title="Secondary amino acid">Secondary amino</a></li> <li><a href="/wiki/Imino_acid" title="Imino acid">Imino acids</a></li> <li><a href="/wiki/D-amino_acids" class="mw-redirect" title="D-amino acids">D-amino acids</a></li> <li><a href="/wiki/Dehydroamino_acid" title="Dehydroamino acid">Dehydroamino acids</a></li></ul> </div></div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Essential_amino_acid&oldid=1258978032">https://en.wikipedia.org/w/index.php?title=Essential_amino_acid&oldid=1258978032</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Amino_acids" title="Category:Amino acids">Amino acids</a></li><li><a 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