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</a> </li> <li id="toc-Reazioni" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Reazioni"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Reazioni</span> </div> </a> <ul id="toc-Reazioni-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Regolazione" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Regolazione"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Regolazione</span> </div> </a> <ul id="toc-Regolazione-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Collegamento_con_il_ciclo_dell'acido_citrico" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Collegamento_con_il_ciclo_dell'acido_citrico"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Collegamento con il ciclo dell'acido citrico</span> </div> </a> <ul id="toc-Collegamento_con_il_ciclo_dell'acido_citrico-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Patologie_del_ciclo_dell'urea" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Patologie_del_ciclo_dell'urea"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Patologie del ciclo dell'urea</span> </div> </a> <ul id="toc-Patologie_del_ciclo_dell'urea-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Storia" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Storia"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Storia</span> </div> </a> <ul id="toc-Storia-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Note" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Note"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Note</span> </div> </a> <ul id="toc-Note-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Bibliografia" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Bibliografia"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Bibliografia</span> </div> </a> <ul id="toc-Bibliografia-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Altri_progetti" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Altri_progetti"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Altri progetti</span> </div> </a> <ul id="toc-Altri_progetti-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Collegamenti_esterni" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Collegamenti_esterni"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>Collegamenti esterni</span> </div> </a> <ul id="toc-Collegamenti_esterni-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="Indice" 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="Mostra/Nascondi l'indice" > <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">Mostra/Nascondi l'indice</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">Ciclo dell'urea</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="Vai a una voce in un'altra lingua. Disponibile in 40 lingue" > <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-40" 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">40 lingue</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%AF%D9%88%D8%B1%D8%A9_%D8%A7%D9%84%D9%8A%D9%88%D8%B1%D9%8A%D8%A7" title="دورة اليوريا - arabo" lang="ar" hreflang="ar" data-title="دورة اليوريا" data-language-autonym="العربية" data-language-local-name="arabo" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9E%D1%80%D0%BD%D0%B8%D1%82%D0%B8%D0%BD%D0%BE%D0%B2_%D1%86%D0%B8%D0%BA%D1%8A%D0%BB" title="Орнитинов цикъл - bulgaro" lang="bg" hreflang="bg" data-title="Орнитинов цикъл" data-language-autonym="Български" data-language-local-name="bulgaro" 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/Ciklus_ureje" title="Ciklus ureje - bosniaco" lang="bs" hreflang="bs" data-title="Ciklus ureje" data-language-autonym="Bosanski" data-language-local-name="bosniaco" 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/Cicle_de_la_urea" title="Cicle de la urea - catalano" lang="ca" hreflang="ca" data-title="Cicle de la urea" data-language-autonym="Català" data-language-local-name="catalano" 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/Mo%C4%8Dovinov%C3%BD_cyklus" title="Močovinový cyklus - ceco" lang="cs" hreflang="cs" data-title="Močovinový cyklus" data-language-autonym="Čeština" data-language-local-name="ceco" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Harnstoffzyklus" title="Harnstoffzyklus - tedesco" lang="de" hreflang="de" data-title="Harnstoffzyklus" data-language-autonym="Deutsch" data-language-local-name="tedesco" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%9A%CF%8D%CE%BA%CE%BB%CE%BF%CF%82_%CF%84%CE%B7%CF%82_%CE%BF%CF%85%CF%81%CE%AF%CE%B1%CF%82" title="Κύκλος της ουρίας - greco" lang="el" hreflang="el" data-title="Κύκλος της ουρίας" data-language-autonym="Ελληνικά" data-language-local-name="greco" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/Urea_cycle" title="Urea cycle - inglese" lang="en" hreflang="en" data-title="Urea cycle" data-language-autonym="English" data-language-local-name="inglese" class="interlanguage-link-target"><span>English</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Urea_ciklo" title="Urea ciklo - esperanto" lang="eo" hreflang="eo" data-title="Urea ciklo" data-language-autonym="Esperanto" data-language-local-name="esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Ciclo_de_la_urea" title="Ciclo de la urea - spagnolo" lang="es" hreflang="es" data-title="Ciclo de la urea" data-language-autonym="Español" data-language-local-name="spagnolo" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DA%86%D8%B1%D8%AE%D9%87_%D8%A7%D9%88%D8%B1%D9%87" title="چرخه اوره - persiano" lang="fa" hreflang="fa" data-title="چرخه اوره" data-language-autonym="فارسی" data-language-local-name="persiano" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Ureakierto" title="Ureakierto - finlandese" lang="fi" hreflang="fi" data-title="Ureakierto" data-language-autonym="Suomi" data-language-local-name="finlandese" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Cycle_de_l%27ur%C3%A9e" title="Cycle de l'urée - francese" lang="fr" hreflang="fr" data-title="Cycle de l'urée" data-language-autonym="Français" data-language-local-name="francese" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Ciclo_da_urea" title="Ciclo da urea - galiziano" lang="gl" hreflang="gl" data-title="Ciclo da urea" data-language-autonym="Galego" data-language-local-name="galiziano" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%9E%D7%A2%D7%92%D7%9C_%D7%94%D7%90%D7%95%D7%A8%D7%99%D7%90%D7%94" title="מעגל האוריאה - ebraico" lang="he" hreflang="he" data-title="מעגל האוריאה" data-language-autonym="עברית" data-language-local-name="ebraico" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Ciklus_ureje" title="Ciklus ureje - croato" lang="hr" hreflang="hr" data-title="Ciklus ureje" data-language-autonym="Hrvatski" data-language-local-name="croato" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Karbamidciklus" title="Karbamidciklus - ungherese" lang="hu" hreflang="hu" data-title="Karbamidciklus" data-language-autonym="Magyar" data-language-local-name="ungherese" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E5%B0%BF%E7%B4%A0%E5%9B%9E%E8%B7%AF" title="尿素回路 - giapponese" lang="ja" hreflang="ja" data-title="尿素回路" data-language-autonym="日本語" data-language-local-name="giapponese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%9A%94%EC%86%8C_%ED%9A%8C%EB%A1%9C" title="요소 회로 - coreano" lang="ko" hreflang="ko" data-title="요소 회로" data-language-autonym="한국어" data-language-local-name="coreano" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Cyclus_ureae" title="Cyclus ureae - latino" lang="la" hreflang="la" data-title="Cyclus ureae" data-language-autonym="Latina" data-language-local-name="latino" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%A6%D0%B8%D0%BA%D0%BB%D1%83%D1%81_%D0%BD%D0%B0_%D1%83%D1%80%D0%B5%D0%B0" title="Циклус на уреа - macedone" lang="mk" hreflang="mk" data-title="Циклус на уреа" data-language-autonym="Македонски" data-language-local-name="macedone" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Kitaran_urea" title="Kitaran urea - malese" lang="ms" hreflang="ms" data-title="Kitaran urea" data-language-autonym="Bahasa Melayu" data-language-local-name="malese" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Ureumcyclus" title="Ureumcyclus - olandese" lang="nl" hreflang="nl" data-title="Ureumcyclus" data-language-autonym="Nederlands" data-language-local-name="olandese" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Ureasyklus" title="Ureasyklus - norvegese nynorsk" lang="nn" hreflang="nn" data-title="Ureasyklus" data-language-autonym="Norsk nynorsk" data-language-local-name="norvegese nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Cykl_ornitynowy" title="Cykl ornitynowy - polacco" lang="pl" hreflang="pl" data-title="Cykl ornitynowy" data-language-autonym="Polski" data-language-local-name="polacco" 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/Ciclo_da_ureia" title="Ciclo da ureia - portoghese" lang="pt" hreflang="pt" data-title="Ciclo da ureia" data-language-autonym="Português" data-language-local-name="portoghese" 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/Ciclul_ureei" title="Ciclul ureei - rumeno" lang="ro" hreflang="ro" data-title="Ciclul ureei" data-language-autonym="Română" data-language-local-name="rumeno" 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%A6%D0%B8%D0%BA%D0%BB_%D0%BC%D0%BE%D1%87%D0%B5%D0%B2%D0%B8%D0%BD%D1%8B" title="Цикл мочевины - russo" lang="ru" hreflang="ru" data-title="Цикл мочевины" data-language-autonym="Русский" data-language-local-name="russo" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Ciklus_ureje" title="Ciklus ureje - serbo-croato" lang="sh" hreflang="sh" data-title="Ciklus ureje" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="serbo-croato" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Mo%C4%8Dovinov%C3%BD_cyklus" title="Močovinový cyklus - slovacco" lang="sk" hreflang="sk" data-title="Močovinový cyklus" data-language-autonym="Slovenčina" data-language-local-name="slovacco" 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/Ciklus_se%C4%8Dnine" title="Ciklus sečnine - sloveno" lang="sl" hreflang="sl" data-title="Ciklus sečnine" data-language-autonym="Slovenščina" data-language-local-name="sloveno" 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/%D0%A6%D0%B8%D0%BA%D0%BB%D1%83%D1%81_%D1%83%D1%80%D0%B5%D1%98%D0%B5" title="Циклус уреје - serbo" lang="sr" hreflang="sr" data-title="Циклус уреје" data-language-autonym="Српски / srpski" data-language-local-name="serbo" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Ureacykeln" title="Ureacykeln - svedese" lang="sv" hreflang="sv" data-title="Ureacykeln" data-language-autonym="Svenska" data-language-local-name="svedese" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%AF%E0%AF%82%E0%AE%B0%E0%AE%BF%E0%AE%AF%E0%AE%BE_%E0%AE%9A%E0%AF%81%E0%AE%B4%E0%AE%B1%E0%AF%8D%E0%AE%9A%E0%AE%BF" title="யூரியா சுழற்சி - tamil" lang="ta" hreflang="ta" data-title="யூரியா சுழற்சி" data-language-autonym="தமிழ்" data-language-local-name="tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%A7%E0%B8%B1%E0%B8%8F%E0%B8%88%E0%B8%B1%E0%B8%81%E0%B8%A3%E0%B8%A2%E0%B8%B9%E0%B9%80%E0%B8%A3%E0%B8%B5%E0%B8%A2" title="วัฏจักรยูเรีย - thailandese" lang="th" hreflang="th" data-title="วัฏจักรยูเรีย" data-language-autonym="ไทย" data-language-local-name="thailandese" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/%C3%9Cre_d%C3%B6ng%C3%BCs%C3%BC" title="Üre döngüsü - turco" lang="tr" hreflang="tr" data-title="Üre döngüsü" data-language-autonym="Türkçe" data-language-local-name="turco" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%A6%D0%B8%D0%BA%D0%BB_%D1%81%D0%B5%D1%87%D0%BE%D0%B2%D0%B8%D0%BD%D0%B8" title="Цикл сечовини - ucraino" lang="uk" hreflang="uk" data-title="Цикл сечовини" data-language-autonym="Українська" data-language-local-name="ucraino" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Chu_tr%C3%ACnh_ure" title="Chu trình ure - vietnamita" lang="vi" hreflang="vi" data-title="Chu trình ure" data-language-autonym="Tiếng Việt" data-language-local-name="vietnamita" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-yo mw-list-item"><a href="https://yo.wikipedia.org/wiki/Urea_cycle" title="Urea cycle - yoruba" lang="yo" hreflang="yo" data-title="Urea cycle" data-language-autonym="Yorùbá" data-language-local-name="yoruba" class="interlanguage-link-target"><span>Yorùbá</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%B0%BF%E7%B4%A0%E5%BE%AA%E7%8E%AF" title="尿素循环 - cinese" lang="zh" hreflang="zh" data-title="尿素循环" data-language-autonym="中文" data-language-local-name="cinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q595994#sitelinks-wikipedia" title="Modifica collegamenti interlinguistici" class="wbc-editpage">Modifica collegamenti</a></span></div> </div> 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class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Strumenti pagine"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Aspetto"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Aspetto</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">sposta nella barra laterale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">nascondi</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">Da Wikipedia, l'enciclopedia libera.</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="it" dir="ltr"><figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Urea_cycle.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/Urea_cycle.svg/350px-Urea_cycle.svg.png" decoding="async" width="350" height="528" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/be/Urea_cycle.svg/525px-Urea_cycle.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/be/Urea_cycle.svg/700px-Urea_cycle.svg.png 2x" data-file-width="620" data-file-height="936" /></a><figcaption>1. <a href="/wiki/Ornitina" title="Ornitina">Ornitina</a><br />2. <a href="/wiki/Carbammilfosfato" title="Carbammilfosfato">Carbammilfosfato</a><br />3. <a href="/wiki/Citrullina" title="Citrullina">Citrullina</a><br />4. <a href="/wiki/Acido_argininsuccinico" title="Acido argininsuccinico">Argininsuccinato</a><br />5. <a href="/wiki/Fumarato" title="Fumarato">Fumarato</a><br />6. <a href="/wiki/Arginina" title="Arginina">Arginina</a><br />7. <a href="/wiki/Urea" title="Urea">Urea</a><br />L-Asp = <a href="/wiki/Aspartato" class="mw-redirect" title="Aspartato">Aspartato</a><br />CPS-1 = Carbammilfosfato sintetasi I<br />OTC = Ornitina transcarbamilasi<br />ASS = Argininsuccinato sintetasi<br />ASL = Argininsuccinato liasi<br />ARG1 = Arginasi 1</figcaption></figure><p> Il <b>ciclo dell'urea</b> (anche detto <b>ciclo dell'ornitina</b> o <b>ciclo dell'oca</b>, per via dei tre amminoacidi coinvolti: <a href="/wiki/Ornitina" title="Ornitina">ornitina</a>, <a href="/wiki/Citrullina" title="Citrullina">citrullina</a> e <a href="/wiki/Arginina" title="Arginina">arginina</a>) è un <a href="/wiki/Ciclo_metabolico" title="Ciclo metabolico">ciclo metabolico</a> presente negli organismi <a href="/wiki/Ureotelici" title="Ureotelici">ureotelici</a> (es. mammiferi e molti anfibi adulti) volto a trasformare l'<a href="/wiki/Ammoniaca" title="Ammoniaca">ammoniaca</a> (altamente tossica) in <a href="/wiki/Urea" title="Urea">urea</a>, affinché possa essere eliminata con le <a href="/wiki/Urina" title="Urina">urine</a>. Nei pesci l'ammoniaca viene escreta come tale, mentre nei rettili e negli uccelli viene trasformata metabolicamente in <a href="/wiki/Acido_urico" title="Acido urico">acido urico</a>. L'ammoniaca è prodotta dal <a href="/wiki/Catabolismo" title="Catabolismo">catabolismo</a> degli <a href="/wiki/Amminoacidi" class="mw-redirect" title="Amminoacidi">amminoacidi</a> e dalle fermentazioni batteriche intestinali. Il ciclo dell'urea avviene nel <a href="/wiki/Fegato" title="Fegato">fegato</a>; tuttavia, teoricamente, anche gli altri tessuti sono in grado di produrre urea in quantità poco rilevanti, disponendo di <a href="/wiki/Arginasi" title="Arginasi">arginasi</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> </p><p>La via metabolica produce ioni <a href="/wiki/Idrogeno" title="Idrogeno">idrogeno</a><style data-mw-deduplicate="TemplateStyles:r140554517">.mw-parser-output .chiarimento{background:#ffeaea;color:#444444}.mw-parser-output .chiarimento-apice{color:#EE0700}@media screen{html.skin-theme-clientpref-night .mw-parser-output .chiarimento{background:rgba(179,36,36,0.21);color:inherit}html.skin-theme-clientpref-night .mw-parser-output .chiarimento-apice{color:#b32424}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .chiarimento{background:rgba(179,36,36,0.21);color:inherit}html.skin-theme-clientpref-os .mw-parser-output .chiarimento-apice{color:#b32424}}</style><span class="chiarimento" title="Queste informazioni non sono comprovate da fonti attendibili."></span><sup class="noprint chiarimento-apice" title="Queste informazioni non sono comprovate da fonti attendibili.">[<i><a href="/wiki/Wikipedia:Uso_delle_fonti" title="Wikipedia:Uso delle fonti">senza fonte</a></i>]</sup> quindi il processo viene regolato negativamente in caso di <a href="/wiki/Acidosi" title="Acidosi">acidosi</a>. </p><p>La reazione netta è: </p><p>NH<sub>4</sub><sup>+</sup> + HCO<sub>3</sub><sup>-</sup> + <a href="/wiki/Aspartato" class="mw-redirect" title="Aspartato">Asp</a> + 3ATP + H<sub>2</sub>O → <a href="/wiki/Urea" title="Urea">Urea</a> + <a href="/wiki/Acido_fumarico" title="Acido fumarico">Acido fumarico</a> + 2ADP + AMP + 2Pi + PPi </p><p>Considerato che si parte dalla reazione tra ammoniaca e <a href="/wiki/Acido_carbonico" title="Acido carbonico">acido carbonico</a> che formano <a href="/wiki/Carbammati" title="Carbammati">carbammato</a> (ovvero l'<a href="/wiki/Ammidi" title="Ammidi">ammide</a> dell'acido carbonico) per avere urea (ovvero la diammide dell'acido carbonico) si nota come una reazione semplice, realizzabile in un passaggio, ma con <a href="/wiki/Energia_di_attivazione" title="Energia di attivazione">energia di attivazione</a> elevata non abbassabile da un singolo <a href="/wiki/Enzima" title="Enzima">enzima</a>, viene nella cellula spezzettata in 5 passaggi energeticamente più favorevoli. Dal ciclo vengono forniti altri metaboliti importanti come l'<a href="/wiki/Arginina" title="Arginina">arginina</a> che, pur essendo un <a href="/wiki/Amminoacido_essenziale" class="mw-redirect" title="Amminoacido essenziale">amminoacido essenziale</a> per l'infanzia, in età adulta è prodotta dal ciclo. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Reazioni">Reazioni</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=1" title="Modifica la sezione Reazioni" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=1" title="Edit section's source code: Reazioni"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable"> <tbody><tr bgcolor="#cccccc"> <th></th> <th><a href="/wiki/Substrato_(biochimica)" title="Substrato (biochimica)">Substrati</a> e <a href="/wiki/Cofattore_(biologia)" title="Cofattore (biologia)">coenzimi</a></th> <th>Prodotti</th> <th><a href="/wiki/Enzima" title="Enzima">Enzima</a></th> <th>Localizzazione </th></tr> <tr> <td><b>1</b></td> <td>NH<sub>4</sub><sup>+</sup> + HCO<sub>3</sub><sup>−</sup> + 2<a href="/wiki/Adenosina_trifosfato" title="Adenosina trifosfato">ATP</a></td> <td><a href="/wiki/Carbammilfosfato" title="Carbammilfosfato">carbamilfosfato</a> + 2<a href="/wiki/Adenosina_difosfato" title="Adenosina difosfato">ADP</a> + P<sub>i</sub></td> <td>Carbamilfosfato sintetasi I</td> <td><a href="/wiki/Mitocondrio" title="Mitocondrio">mitocondrio</a> </td></tr> <tr> <td><b>2</b></td> <td>carbammilfosfato + <a href="/wiki/Ornitina" title="Ornitina">ornitina</a></td> <td><a href="/wiki/Citrullina" title="Citrullina">citrullina</a> + P<sub>i</sub></td> <td><a href="/wiki/Ornitina_carbammiltransferasi" title="Ornitina carbammiltransferasi">Ornitina transcarbamilasi</a></td> <td>mitocondrio </td></tr> <tr> <td><b>3</b></td> <td>citrullina + <a href="/wiki/Acido_aspartico" title="Acido aspartico">aspartato</a> + ATP</td> <td><a href="/wiki/Acido_argininsuccinico" title="Acido argininsuccinico">argininsuccinato</a> + <a href="/wiki/Adenosina_monofosfato" title="Adenosina monofosfato">AMP</a> + <a href="/wiki/Pirofosfato" title="Pirofosfato">PP<sub>i</sub></a></td> <td>Argininsuccinato sintetasi</td> <td><a href="/wiki/Citosol" title="Citosol">citosol</a> </td></tr> <tr> <td><b>4</b></td> <td>argininsuccinato</td> <td><a href="/wiki/Arginina" title="Arginina">arginina</a> + <a href="/wiki/Fumarato" title="Fumarato">fumarato</a></td> <td>Argininsuccinato liasi</td> <td>citosol </td></tr> <tr> <td><b>5</b></td> <td>arginina + H<sub>2</sub>O</td> <td>ornitina + <a href="/wiki/Urea" title="Urea">urea</a></td> <td><a href="/wiki/Arginasi" title="Arginasi">Arginasi</a></td> <td>citosol </td></tr></tbody></table> <p>Il <b>ciclo dell'urea</b> inizia con la formazione di <a href="/wiki/Carbamilfosfato" class="mw-redirect" title="Carbamilfosfato">carbamilfosfato</a>, tramite la condensazione del <a href="/wiki/Catione" title="Catione">catione</a> <a href="/wiki/Ammonio" title="Ammonio">ammonio</a> NH<sub>4</sub><sup>+</sup>, l'anione idrogenocarbonato (bicarbonato) HCO<sub>3</sub><sup>-</sup> e una molecola di fosfato inorganico, catalizzata dalla <a href="/w/index.php?title=Carbamilfosfato_sintetasi_I&action=edit&redlink=1" class="new" title="Carbamilfosfato sintetasi I (la pagina non esiste)">carbamilfosfato sintetasi I</a>, tramite dispendio di due molecole di <a href="/wiki/Adenosina_trifosfato" title="Adenosina trifosfato">ATP</a>. Successivamente, il <a href="/wiki/Carbamilfosfato" class="mw-redirect" title="Carbamilfosfato">carbamilfosfato</a> viene fatto condensare con una molecola di <a href="/wiki/Ornitina" title="Ornitina">ornitina</a> per dare <a href="/wiki/Citrullina" title="Citrullina">citrullina</a>; la reazione è catalizzata dalla <a href="/wiki/Ornitina_carbammiltransferasi" title="Ornitina carbammiltransferasi">ornitina transcarbamilasi</a>. La citrullina formata esce dal <a href="/wiki/Mitocondrio" title="Mitocondrio">mitocondrio</a> per andare nel <a href="/wiki/Citosol" title="Citosol">citosol</a>, qui viene fatta condensare con una molecola di <a href="/wiki/Aspartato" class="mw-redirect" title="Aspartato">aspartato</a> dalla <a href="/w/index.php?title=Argininosuccinato_sintetasi&action=edit&redlink=1" class="new" title="Argininosuccinato sintetasi (la pagina non esiste)">argininosuccinato sintetasi</a> formando <a href="/wiki/Acido_argininsuccinico" title="Acido argininsuccinico">argininosuccinato</a>. L'argininosuccinato viene scisso in arginina e <a href="/wiki/Fumarato" title="Fumarato">fumarato</a> dall'argininosuccinato liasi ed il fumarato viene indirizzato verso il <a href="/wiki/Ciclo_di_Krebs" title="Ciclo di Krebs">ciclo di Krebs</a>, il fumarato è trasformato dalla fumarasi citoplasmatica in malato e questo ossidato in ossaloacetato, che viene poi transaminato in aspartato. Infine, l'arginina è trasformata in ornitina e <a href="/wiki/Urea" title="Urea">urea</a> dall'<a href="/wiki/Arginasi" title="Arginasi">arginasi</a>, e quindi l'urea viene trasportata dal flusso ematico verso i <a href="/wiki/Reni" class="mw-redirect" title="Reni">reni</a> e l'ornitina può essere utilizzata per un altro ciclo. L'urea viene poi escreta con le urine. Sebbene tutti i tessuti dispongano di arginasi, e dunque della capacità di compiere il ciclo, è solamente il fegato ad essere ricco degli enzimi del ciclo ed in particolare della carbamil-fosfato sintetasi di tipo I e la ornitina transcarbamilasi. </p> <div class="mw-heading mw-heading2"><h2 id="Regolazione">Regolazione</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=2" title="Modifica la sezione Regolazione" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=2" title="Edit section's source code: Regolazione"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Il ciclo dell'urea subisce una <i>duplice regolazione</i>: una a lungo e una a breve termine. </p><p>Nel primo caso si osserva come la modulazione dell'attività catalitica degli enzimi dipenda dalla composizione della dieta: infatti, nel caso in cui si assuma una dieta ricca di proteine, i cinque enzimi della via metabolica vengono sintetizzati molto più velocemente poiché si compensa il rilascio dei gruppi amminici successivamente alla degradazione delle proteine digerite. La stessa situazione si osserva nel caso in cui si è sottoposti ad un periodo di digiuno, ma, in questo caso, la fonte delle proteine e dei gruppi amminici è differente poiché proviene dalla degradazione delle proteine muscolari. </p><p>La regolazione a "breve termine", invece, consiste nella produzione di <a href="/w/index.php?title=N-acetilglutammato&action=edit&redlink=1" class="new" title="N-acetilglutammato (la pagina non esiste)">N-acetilglutammato</a>, <a href="/w/index.php?title=Attivatore_allosterico&action=edit&redlink=1" class="new" title="Attivatore allosterico (la pagina non esiste)">attivatore allosterico</a> dell'enzima carbamil fosfato sintetasi I. Questo composto viene formato a partire da una molecola di <a href="/wiki/Acido_glutammico" title="Acido glutammico">glutammato</a> e una di <a href="/wiki/Acetil-coenzima_A" title="Acetil-coenzima A">acetil-CoA</a>, grazie all'azione dell'enzima <a href="/wiki/Amminoacido_N-acetiltransferasi" title="Amminoacido N-acetiltransferasi">N-acetilglutammato sintasi</a>, a sua volta attivato grazie ad un aumento delle concentrazioni di arginina (intermedio del ciclo dell'urea). </p> <div class="mw-heading mw-heading2"><h2 id="Collegamento_con_il_ciclo_dell'acido_citrico"><span id="Collegamento_con_il_ciclo_dell.27acido_citrico"></span>Collegamento con il ciclo dell'acido citrico</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=3" title="Modifica la sezione Collegamento con il ciclo dell'acido citrico" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=3" title="Edit section's source code: Collegamento con il ciclo dell'acido citrico"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Il ciclo dell'urea e il <a href="/wiki/Ciclo_di_Krebs" title="Ciclo di Krebs">ciclo dell'acido citrico</a> sono cicli indipendenti, ma collegati. Uno degli atomi di azoto nel ciclo dell'urea è ottenuto dalla transaminazione dell'ossalacetato in aspartato.<sup id="cite_ref-:0_2-0" class="reference"><a href="#cite_note-:0-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> Il fumarato che viene prodotto nella fase tre è anche un intermedio nel ciclo dell'acido citrico e viene riportato a quel ciclo. <sup id="cite_ref-:0_2-1" class="reference"><a href="#cite_note-:0-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Patologie_del_ciclo_dell'urea"><span id="Patologie_del_ciclo_dell.27urea"></span>Patologie del ciclo dell'urea</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=4" title="Modifica la sezione Patologie del ciclo dell'urea" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=4" title="Edit section's source code: Patologie del ciclo dell'urea"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Una rara <a href="/wiki/Malattia_genetica" title="Malattia genetica">malattia genetica</a> che colpisce circa una persona su 35.000 negli Stati Uniti.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> Possono verificarsi difetti genetici negli enzimi coinvolti nel ciclo. Le mutazioni portano a carenze dei vari enzimi e trasportatori coinvolti nel ciclo dell'urea e causano disturbi del ciclo dell'urea.<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> Se gli individui con un difetto in uno dei sei enzimi utilizzati nel ciclo ingeriscono aminoacidi oltre a quanto necessario per il fabbisogno giornaliero, l'ammoniaca prodotta non sarà in grado di essere convertita in urea. Questi individui possono sperimentare <a href="/w/index.php?title=Iperammonemia&action=edit&redlink=1" class="new" title="Iperammonemia (la pagina non esiste)">iperammonemia</a> o l'accumulo di un ciclo intermedio. </p> <ul><li>Deficit di <a href="/wiki/N-acetilglutammato_sintasi" class="mw-redirect" title="N-acetilglutammato sintasi">N-acetilglutammato sintasi</a></li> <li>Carenza di carbamoilfosfato sintetasi</li> <li>Carenza di ornitina transcarbamilasi</li> <li>Citrullinemia (carenza di acido argininosuccinico sintasi)</li> <li>Aciduria argininosuccinica (carenza di acido lisasi argininosuccinica)</li> <li>Argininemia (carenza di arginasi)</li> <li>Iperornitinemia, iperammonemia, sindrome da omocitrullinuria (carenza del trasportatore mitocondriale dell'ornitina)</li> <li>Morbo di Alzheimer (eccedenza di arginasi)</li> <li>Diabete di tipo 2 (surplus di arginasi)</li> <li>Alta pressione sanguigna (surplus di arginasi)</li></ul> <p>La maggior parte dei disturbi del ciclo dell'urea sono associati all'iperammonemia, tuttavia l'argininemia e alcune forme di aciduria arginino-succinica non presentano ammoniaca elevata. </p> <div class="mw-heading mw-heading2"><h2 id="Storia">Storia</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=5" title="Modifica la sezione Storia" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=5" title="Edit section's source code: Storia"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Il ciclo dell'urea fu il primo ciclo metabolico a essere delucidato. Venne chiarito da <a href="/wiki/Hans_Adolf_Krebs" title="Hans Adolf Krebs">Hans Adolf Krebs</a> e <a href="/w/index.php?title=Kurt_Henseleit&action=edit&redlink=1" class="new" title="Kurt Henseleit (la pagina non esiste)">Kurt Henseleit</a> nel <a href="/wiki/1932" title="1932">1932</a>, ma solo successivamente <a href="/w/index.php?title=Sarah_Ratner&action=edit&redlink=1" class="new" title="Sarah Ratner (la pagina non esiste)">Sarah Ratner</a> e <a href="/w/index.php?title=Philip_Cohen&action=edit&redlink=1" class="new" title="Philip Cohen (la pagina non esiste)">Philip Cohen</a> descrissero in dettaglio le singole reazioni. </p> <div class="mw-heading mw-heading2"><h2 id="Note">Note</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=6" title="Modifica la sezione Note" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=6" title="Edit section's source code: Note"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><a href="#cite_ref-1"><b>^</b></a> <span class="reference-text"><cite class="citation libro" style="font-style:normal"> <span style="font-style:italic;">Biochimica Medica - Strutturale, metabolica e funzionale; IV Edizione</span>, PICCIN, p. 396.</cite></span> </li> <li id="cite_note-:0-2"><span class="mw-cite-backlink"><b>^</b> <sup><i><a href="#cite_ref-:0_2-0">a</a></i></sup> <sup><i><a href="#cite_ref-:0_2-1">b</a></i></sup></span> <span class="reference-text"><cite class="citation pubblicazione" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) G. E. Shambaugh, <a rel="nofollow" class="external text" href="https://academic.oup.com/ajcn/article/30/12/2083/4650835"><span style="font-style:italic;">Urea biosynthesis I. The urea cycle and relationships to the citric acid cycle</span></a>, in <span style="font-style:italic;">The American Journal of Clinical Nutrition</span>, vol. 30, n. 12, 1º dicembre 1977, pp. 2083–2087, <a href="/wiki/Digital_object_identifier" title="Digital object identifier">DOI</a>:<a rel="nofollow" class="external text" href="https://dx.doi.org/10.1093%2Fajcn%2F30.12.2083">10.1093/ajcn/30.12.2083</a>. <small>URL consultato l'11 ottobre 2019</small>.</cite></span> </li> <li id="cite_note-3"><a href="#cite_ref-3"><b>^</b></a> <span class="reference-text"><cite class="citation pubblicazione" style="font-style:normal"> Marshall L. Summar, Stefan Koelker e Debra Freedenberg, <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364413/"><span style="font-style:italic;">The incidence of urea cycle disorders</span></a>, in <span style="font-style:italic;">Molecular genetics and metabolism</span>, vol. 110, n. 0, 2013, pp. 179–180, <a href="/wiki/Digital_object_identifier" title="Digital object identifier">DOI</a>:<a rel="nofollow" class="external text" href="https://dx.doi.org/10.1016%2Fj.ymgme.2013.07.008">10.1016/j.ymgme.2013.07.008</a>. <small>URL consultato l'11 ottobre 2019</small>.</cite></span> </li> <li id="cite_note-4"><a href="#cite_ref-4"><b>^</b></a> <span class="reference-text"><cite class="citation pubblicazione" style="font-style:normal"> <span style="font-style:italic;">Cox, Michael (2013-01-01). Lehninger Principles of Biochemistry. Freeman</span>.</cite></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Bibliografia">Bibliografia</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=7" title="Modifica la sezione Bibliografia" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=7" title="Edit section's source code: Bibliografia"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>R.H. Abeles, P.A. Frej, W.P. Jencks, <i>Biochimica</i>, traduzione italiana, ed. Piccin, Padova, 1994</li> <li>A.R. Katritzky, J.M. Lagowski, <i>Principi della Chimica Eterociclica</i>, traduzione italiana, CEA, Milano, 1968</li> <li>G.A. Pagani, A. Abbotto, <i>Chimica Eterociclica</i>, Piccin, Padova, 1995</li> <li>D.L. Nelson, M.M. Cox, "I Principi Di Biochimica Di Lehninger", Zanichelli, 2006</li></ul> <div class="mw-heading mw-heading2"><h2 id="Altri_progetti">Altri progetti</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=8" title="Modifica la sezione Altri progetti" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=8" title="Edit section's source code: Altri progetti"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <div id="interProject" class="toccolours" style="display: none; clear: both; margin-top: 2em"><p id="sisterProjects" style="background-color: #efefef; color: black; font-weight: bold; margin: 0"><span>Altri progetti</span></p><ul title="Collegamenti verso gli altri progetti Wikimedia"> <li class="" title=""><span class="plainlinks" title="commons:Category:Urea cycle"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:Urea_cycle?uselang=it">Wikimedia Commons</a></span></li></ul></div> <ul><li><span typeof="mw:File"><a href="https://commons.wikimedia.org/wiki/?uselang=it" title="Collabora a Wikimedia Commons"><img alt="Collabora a Wikimedia Commons" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png" decoding="async" width="18" height="24" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/27px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/36px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> <span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/?uselang=it">Wikimedia Commons</a></span> contiene immagini o altri file su <b><span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:Urea_cycle?uselang=it">ciclo dell'urea</a></span></b></li></ul> <div class="mw-heading mw-heading2"><h2 id="Collegamenti_esterni">Collegamenti esterni</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Ciclo_dell%27urea&veaction=edit&section=9" title="Modifica la sezione Collegamenti esterni" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Ciclo_dell%27urea&action=edit&section=9" title="Edit section's source code: Collegamenti esterni"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="http://homepage.ufp.pt/pedros/bq/urea.htm"><span style="font-style:italic;">Il ciclo dell'urea</span></a>, su <span style="font-style:italic;">homepage.ufp.pt</span>.</cite></li></ul> <style data-mw-deduplicate="TemplateStyles:r141815314">.mw-parser-output .navbox{border:1px solid #aaa;clear:both;margin:auto;padding:2px;width:100%}.mw-parser-output .navbox th{padding-left:1em;padding-right:1em;text-align:center}.mw-parser-output .navbox>tbody>tr:first-child>th{background:#ccf;font-size:90%;width:100%;color:var(--color-base,black)}.mw-parser-output .navbox_navbar{float:left;margin:0;padding:0 10px 0 0;text-align:left;width:6em}.mw-parser-output .navbox_title{font-size:110%}.mw-parser-output .navbox_abovebelow{background:#ddf;font-size:90%;font-weight:normal}.mw-parser-output .navbox_group{background:#ddf;font-size:90%;padding:0 10px;white-space:nowrap}.mw-parser-output .navbox_list{font-size:90%;width:100%}.mw-parser-output .navbox_list a{white-space:nowrap}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_odd{background:#fdfdfd;color:var(--color-base,black)}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_even{background:#f7f7f7;color:var(--color-base,black)}.mw-parser-output .navbox a.mw-selflink{color:var(--color-base,black)}.mw-parser-output .navbox_center{text-align:center}.mw-parser-output .navbox .navbox_image{padding-left:7px;vertical-align:middle;width:0}.mw-parser-output .navbox+.navbox{margin-top:-1px}.mw-parser-output .navbox .mw-collapsible-toggle{font-weight:normal;text-align:right;width:7em}body.skin--responsive .mw-parser-output .navbox_image img{max-width:none!important}.mw-parser-output .subnavbox{margin:-3px;width:100%}.mw-parser-output .subnavbox_group{background:#e6e6ff;padding:0 10px}@media screen{html.skin-theme-clientpref-night .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-night .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-night .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-os .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-os .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}</style><table class="navbox mw-collapsible autocollapse noprint metadata" id="navbox-Metabolismo"><tbody><tr><th colspan="2"><div class="navbox_navbar"><div class="noprint plainlinks" style="background-color:transparent; padding:0; font-size:xx-small; color:var(--color-base, #000000); white-space:nowrap;"><a href="/wiki/Template:Metabolismo" title="Template:Metabolismo"><span title="Vai alla pagina del template">V</span></a> · <a href="/wiki/Discussioni_template:Metabolismo" title="Discussioni template:Metabolismo"><span title="Discuti del template">D</span></a> · <a class="external text" href="https://it.wikipedia.org/w/index.php?title=Template:Metabolismo&action=edit"><span title="Modifica il template. Usa l'anteprima prima di salvare">M</span></a></div></div><span class="navbox_title">Metabolismo</span></th></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Metabolismo" title="Metabolismo">Metabolismo</a></th><td colspan="1" class="navbox_list navbox_odd"><a href="/wiki/Via_metabolica" title="Via metabolica">Via metabolica</a><b> ·</b> <a href="/wiki/Catena_metabolica" title="Catena metabolica">Catena metabolica</a><b> ·</b> <a href="/wiki/Ciclo_metabolico" title="Ciclo metabolico">Ciclo metabolico</a><b> ·</b> <a href="/wiki/Via_anfibolica" title="Via anfibolica">Via anfibolica</a></td></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Catabolismo" title="Catabolismo">Catabolismo</a></th><td colspan="1" class="navbox_list navbox_even"><a href="/wiki/Glicolisi" title="Glicolisi">Glicolisi</a><b> ·</b> <a href="/wiki/Beta_ossidazione" title="Beta ossidazione">Beta ossidazione</a><b> ·</b> <a href="/wiki/Decarbossilazione_ossidativa_del_piruvato" title="Decarbossilazione ossidativa del piruvato">Decarbossilazione ossidativa del piruvato</a><b> ·</b> <a href="/wiki/Ciclo_di_Krebs" title="Ciclo di Krebs">Ciclo di Krebs</a><b> ·</b> <a href="/wiki/Fosforilazione_ossidativa" title="Fosforilazione ossidativa">Fosforilazione ossidativa</a><b> ·</b> <a href="/wiki/Glicogenolisi" title="Glicogenolisi">Glicogenolisi</a><b> ·</b> <a href="/wiki/Chetogenesi" title="Chetogenesi">Chetogenesi</a></td></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Anabolismo" title="Anabolismo">Anabolismo</a></th><td colspan="1" class="navbox_list navbox_odd"><a href="/wiki/Gluconeogenesi" title="Gluconeogenesi">Gluconeogenesi</a><b> ·</b> <a href="/wiki/Sintesi_proteica" title="Sintesi proteica">Sintesi proteica</a><b> ·</b> <a href="/wiki/Sintesi_degli_acidi_grassi" title="Sintesi degli acidi grassi">Sintesi degli acidi grassi</a><b> ·</b> <a href="/wiki/Glicogenosintesi" title="Glicogenosintesi">Glicogenosintesi</a><b> ·</b> <a href="/wiki/Via_dei_pentoso_fosfati" title="Via dei pentoso fosfati">Via dei pentoso fosfati</a><b> ·</b> <a href="/w/index.php?title=Gliceroneogenesi&action=edit&redlink=1" class="new" title="Gliceroneogenesi (la pagina non esiste)">Gliceroneogenesi</a></td></tr><tr><th colspan="1" class="navbox_group">Altre voci</th><td colspan="1" class="navbox_list navbox_even"><a href="/wiki/Ciclo_di_Cori" title="Ciclo di Cori">Ciclo di Cori</a><b> ·</b> <a href="/wiki/Degradazione_degli_amminoacidi" title="Degradazione degli amminoacidi">Degradazione degli amminoacidi</a><b> ·</b> <a href="/wiki/Fotosintesi_clorofilliana" title="Fotosintesi clorofilliana">Fotosintesi clorofilliana</a><b> ·</b> <a href="/wiki/Fotorespirazione" title="Fotorespirazione">Fotorespirazione</a><b> ·</b> <a href="/wiki/Ciclo_di_Calvin" title="Ciclo di Calvin">Ciclo di Calvin</a><b> ·</b> <a class="mw-selflink selflink">Ciclo dell'urea</a><b> ·</b> <a href="/wiki/Fermentazione" title="Fermentazione">Fermentazione</a><b> ·</b> <a href="/wiki/Ciclo_del_gliossilato" title="Ciclo del gliossilato">Ciclo del gliossilato</a></td></tr></tbody></table> <div class="noprint" style="width:100%; 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