Umjikelo Ornithine: scheme reaction, inkcazelo, ukuphazamiseka yokucolwa

Ukuba umzimba womntu ukugcina umsebenzi oqhelekileyo, oko liqulunqe iindlela ukususa izinto eziyityhefu. Phakathi kwabo, ammonia - ekupheleni-yimveliso yokucolwa of initrogen, xa iiprotheni ethile. H. ₃ liseyityhefu eziphilayo, kwaye nayiphi na ityhefu ofakwe ngenkqubo excretory. Kodwa ngaphambi kokuba ammonia ivavanywa uthotho reactions ezilandelelanayo, ekuthiwa umjikelo ornithine.

Types of nitrogen ukutya

Ayizizo zonke izilwanyana luphawulwa ukukhutshwa ammonia kokusingqongileyo. Alternative izinto nitrogen yokucolwa yokugcina uric acid kunye urea. Ngako oko, iindidi ezintathu kuthiwa nitrogen ukutya, ngokuxhomekeke nantonina.

uhlobo Ammoniotelichesky. Le into yokugqibela apha ammonia. It is a igesi ezingenambala enyibilikayo emanzini. Ammonioteliya uphawu zonke iintlanzi abahlala amachibi ityuwa.

uhlobo Ureotelic. Izilwanyana, obubonakala ngokuba yincwadi evuliweyo ureoteliya, khupha kokusingqongileyo urea. Imizekelo iquka iintlanzi amatsha, izilwanyana eziphila emhlabeni nasemanzini, kunye ezanyisayo, kuquka umntu.

uhlobo Urikotelichesky. Nanga abo abameli zehlabathi yezilwanyana, apho metabolites yokugcina ziikristale of uric acid. Le ekhobokisayo njengoko imveliso zenitrogen lokugaya luyenzeka iintaka ezirhubuluzayo.

Kuyo nayiphi na yezi meko, ingxaki imveliso exchange yokugqibela - yinto ukususwa okungeyomfuneko nitrogen eziphilayo. Ukuba oku akwenzeki, kukho iiseli ixabiso kunye inhibition yokusabela ebalulekileyo.

Yintoni urea?

Urea - yinto amide ye asidi. It amiliswe ukusuka ammonia, icarbon dioxide, nitrogen kunye namaqela amino kwezinto ezithile ngexesha abasabela komjikelo ornithine. Urea - ukhethe imveliso izilwanyana ureotelic, kuquka abantu.

Urea yenye yeendlela obugqithisileyo nitrogen zinomgutyulo emzimbeni. Ukuqulunqwa kwale nto niya kubanyathela umsebenzi njengoko siphu- urea - ammonia na awunatyhefu kwiiseli zabantu.

Ngexesha lokulungiswa 100 g iiprothini umchamo wendalo ezahlukeneyo limi 20-25 g urea. Le nto iya kuhlanganiswa esibindini, yaye ke ngalo igazi engena nephron of wezintso kwaye kwazona kwi yokuchama.

Isibindi - umzimba engundoqo urea

Xa umzimba womntu akukho iseli enjalo, nto leyo eya kuba kuyo ngokupheleleyo zonke enzymes komjikelo ornithine. Ukongeza hepatocytes, kunjalo. umsebenzi iseli Hepatic nje kuphela kuyondelelaniswe nokonakaliswa mpilo, kodwa nokuphunyezwa zonke reactions urea yokuqaphela.

Phantsi Umjikelo efanelekileyo inkcazelo ornithine into yokuba kuphela kwendlela ukususa nitrogen emzimbeni. Ukuba, xa kusenziwa, ukuba zinqanda kuyondelelaniswe okanye iqhosha intshukumo enzyme urea zokumisa kuyondelelaniswe nomzimba zifa ukusuka ammonia agqithisileyo egazini.

umjikelezo Ornithine. reactions ezinto

Umjikelo urea yokuqaphela lwenzeka ngokwamanqanaba eziliqela. Iyonke Umjikelo ornithine umzobo thaca ngezantsi (imifanekiso), kwaye ke ngoko ukuhlalutya indlela ngamnye. Izigaba ezimbini zokuqala uthathe indawo ngqo kwi mitochondria iiseli zesibindi.

H. ₃ idityaniswe icarbon dioxide kunye nenkcitho iimolekyuli ezimbini ATP. Ngenxa reactions-eneji karbamoilfosfat kuyilwa, leyo iqulathe amandla bond. Catalyzes le nkqubo enzayimi karbamoilfosfat synthetase.

Karbamoilfosfat idityaniswe ornithine phantsi yintshukumo enzyme ornithine carbamoyl transferase. Ngenxa yoko, amandla iqhina ibhuqiwe, kodwa iindleko zamandla ayo sidala citrulline.

Izigaba yesithathu elandela uthathe indawo kungekhona mitochondria yaye kukho icytoplasm of hepatocytes.

Ingaba ngumbala phakathi citrulline kunye aspartate. C 1 inkcitho ATP molecule kunye arginine succinate enzyme arginine succinate synthase kwakhiwa.

Arginine succinate kunye enzyme arginine succinate lyase lwanamathela arginine kwaye fumarate.

Arginine phambi kwamanzi phantsi inyathelo arginase lwanamathela ornithine (reaction 1) kunye urea (imveliso yokugqibela). Umjikelo iye yavalwa.

Energy Umjikelo urea yokuqaphela

Umjikelo Ornithine - walidla inkqubo-eneji olunzulu apho iimolekyuli bond eneji adenosine triphosphate (ATP). Kuyo yonke indlela, 5 3 benziwa molecule ndawonye ADP. Ukongeza, i-eneji esetyenziswa kwi ukuthuthwa kwezinto ukusuka mitochondria ukuya kukho icytoplasm vice versa. Phi ATP?

Fumarate, leyo kwasekwa basabela yesine zingasetyenziswa njenge zeendawana kumjikelo asidi tricarboxylic. Ngexesha Yindibanisela malate fumarate NADPH eyabelwe, nto leyo ebangela 3 iimolekyuli ATP.

Indlela deamination of glutamate kudlala indima kunikezelo iiseli zesibindi amandla. Apha imali 3 iimolekyuli ATP eziphezu njini urea.

Ummiselo yomsebenzi komjikelo ornithine

Ngokwesiqhelo, le iqonga urea amagama reaction isebenza kwi-60% yeenqobo kunokwenzeka. Nokonyuka umxholo iiprothini ukutya reactions yanda, nto leyo ekhokelela kucikizeko ephakamileyo ngokubanzi. Ukuphazamiseka umzimba zomjikelo ornithine ambona amandla aphezulu emzimbeni kunye nokuzila ukudla ixesha elide, xa umzimba uqalisa ukubola iiproteni alo.

UmMiselo komjikelo ornithine kungenziwa kwinqanaba ezinto eziphilayo. Apha, le thagethi i-enzayim zaseprayimari karbamoilfosfat synthetase. isilumeki yayo allosteric yi N-acetyl-glutamate. Xa umxholo wayo eziphakamileyo umzimba urea reactions kuyondelelaniswe kuqhelekile. Ngenxa yokunqongophala iziyobisi okanye uhlobo zayo, glutamate kunye acetyl-awula, umjikelo ornithine uphelelwa umthwalo wayo ezisebenzayo.

Unxibelelwano Umjikelo urea yokuqaphela, Krebs umjikelo

Ukusabela zombini iinkqubo kuqhubeka isizalo ayo. Oku kunika ithuba lokuba inxaxheba mbandela eziphilayo kwiinkqubo ezimbini ezinto eziphilayo.

CO ₂ adenosine, leyo akhiwa kumjikelo citric acid, na uhlobo karbamoilfosfata. ATP nayo mthombo obalulekileyo amandla.

Umjikelo Ornithine, zinto zenzeka kwi hepatocytes kwesibindi, - njengomthombo fumarate, omnye substrates ezinkulu somjikelo Krebs. Ngaphezu koko, le nto ngenxa yokusabela ezininzi stepwise bangela aspartate, nto leyo isetyenziswa biosynthesis komjikelo ornithine. Ukusabela ebandakanya NADPH fumarate na umthombo, enokusetyenziswa ukuba phosphorylate ADP ku ATP.

Intsingiselo begazi komjikelo ornithine

Ubuninzi ye-nitrogen engena umzimba ngaphakathi iiprothini. Xa nethe le acid asidi zitshatyalalisiwe, ammonia kwenziwa ibe yimveliso ekupheleni ukutya. Umjikelo Ornithine - ezininzi kuThixo reactions ilandelelana, umsebenzi engundoqo apho ityhefu H. ₃ nenguqulelo yayo urea. Urea, amdaka kulo nephron wezintso kwaye kwazona kwi yokuchama.

Ukongeza, ngu-ornithine umjikelezo ngumthombo arginine - enye asidi kubalulekile acid.

Ukungaqheleki kule njini urea kunokukhokelela izifo ezifana hyperammonemia. Le ngezifo luphawulwa i ndzo elingakumbi Ammonium ion H. _{4 ⁺} egazini. Ezi ion ichaphazele ibubomi kumzimba, ukuvalwa okanye kuyehla iinkqubo ezithile ezibalulekileyo. Indiva lo sifo kukhokelela ekufeni.