Chain yokuphefumla: enzyme ezisebenzayo

Zonke abasabela kwemichiza kwi iiseli nayiphi ephilayo kwenzeka ngenkcitho amandla. chain yokuphefumla - ukulandelelana izakhiwo ezithile akhiwe kwi inwebu engaphakathi mitochondria kukhonza ukuze kwakhiwe ATP. Adenosine ngumthombo ubhetyebhetye wamandla kwaye inokuqokelelana i kJ-80 ukuya kwezili-120.

Nokuphefumla electron chain - ntoni na?

Elektroni kunye protons zidlala indima ebalulekileyo kwimfundo eneji. Enza umahluko ombane kumacala ahlukeneyo inwebu ye-mitochondria ukuba ivelisa isiphakamiso kwe amasuntswana - yangoku. chain zosulele ngokuphefumla (it njl, electron sothutho chain) ungumlamli kwi ukutshintshwa amasuntswana kakuhle ityala kwisithuba intermembrane kunye amasuntswana kakubi etsalwayo Ebubanzini inwebu engaphakathi mitochondria.

Indima ephambili ekubunjweni amandla bobabo kwi ATP-synthase. Le iseti oluntsonkothileyo yamandla liyitshintshe ulwalathiso Proton sindululo kwi amaqhina zamandla ezinto eziphilayo. Ngendlela, ukuba phantse twatse isakhiwo ifumaneka kwi chloroplasts zezityalo.

Kunye izakhiwo ezo enzyme chain sokuphefumla

ukudluliselwa Electron lukhatshwa reactions kwemichiza phambi kwenkqubo enzyme. Ezi izinto eziphila esebenzayo, iikopi ezininzi zawo izakhiwo kwisakhiwo esikhulu, bakhonza njengabalamli kwi ukutshintshwa electron.

Izakhiwo chain nokuphefumla - amacandelo ngundoqo zothutho kwamasuntswana icala. Iyonke kwi inwebu engaphakathi ayo 4 wesiseko enjalo, kwakunye ATP synthase. Zonke ezi zakhiwo babelana injongo efanayo - ukurhangqa etc electron ukugqithiselwa protons hydrogen kwisithuba intermembrane kwaye, ngenxa yoko, le Yindibanisela ATP.

Esi sakhiwo Sisihloko iimolekyuli protein, phakathi apho kukho enzyme, noshowo kunye neeproteni siphawula. Ngalinye kwizakhiwo 4 ekuzalisekiseni kuphela wakhe luphawu, umsebenzi. Makhe sibone apho imisebenzi kwi etc asondeze ezi zakhiwo.

I complex

Ukutshintshelwa electron kwi embindini inwebu ayo indima ephambili ngoku udlalwa nge chain sokuphefumla. Ukuphelisa abasabela protons hydrogen electron lokuhamba nabo - enye abasabela eziphambili NJL Iseti yokuqala umxokelelwane zothutho luthatha molecule nad * H + (izilwanyana) okanye NADP * H + (izityalo), ilandelwe yi cleavage le protons ezine hydrogen. Enyanisweni, ngenxa yale indlela entsonkothileyo zengqo- I ekwabizwa ngokuba NADH - dehydrogenase (igama transcriptase central).

Ukubunjwa dehydrogenase iiproteni yentsimbi-sulphur complex ziquka iintlobo-3, kwaye flavin mononucleotide (FMN).

complex II

Ukusebenza kwalo complex singabandakanyi ukugqithiselwa protons hydrogen kwisithuba intermembrane. Umsebenzi iphambili yale sakhiwo yokubonelela electron eyongezelelweyo kwikhonkco yothutho electron ngokusebenzisa succinate igcwala. Central enzyme complex - succinate-ubiquinone oxidoreductase, leyo catalyzes i cleavage of elektroni ukusuka succinic acid noTshintshiselwano ubiquinone yi lipophilic.

Umniki protons hydrogen electron kwisakhiwo yesibini nalo mkhuba * H _2. Noko ke, flavin ukusebenza adenine dinucleotide ngaphantsi kunolo analogue zayo - nad okanye NADP * H * H.

Le composition II iquka iintlobo ezintathu iiprotheni yentsimbi-sulphur ezintsonkothileyo central oxidoreductase enzyme succinate.

complex III

Ilungu elandelayo ye-akhawunti, etc iqulathe cytochrome b ₅₅₆ b _560, kunye c _1, kwakunye yentsimbi-sulphur protein Risk. Employment of the iseti lesithathu lu dityanisiwe ukutshintshwa protons ezimbini hydrogen kwisithuba intermembrane, kunye electron ukusuka ubiquinone lipophilic ukuba cytochrome C.

Risk osemqoka protein kukuba esixutywe ngamanqatha. Nezinye iiproteni yale iqela ndadibana nabo kwizakhiwo ze-chain yokuphefumla, amanzi-emanzini. Olu phawu kuchaphazela ukuma iimolekyuli iiprothini Ebubanzini inwebu engaphakathi ayo.

Iseti lesithathu lwemisebenzi njengoko ubiquinone-cytochrome c oxidoreductase.

IV complex

Yena complex cytochrome-oxidant leyo kuyo lokugqibela NJL umsebenzi wayo ukutshintshela electron ukusuka cytochrome c ngenxa atom ioksijini. Kamva embi icala O athom aya kusabela kunye protons hydrogen ukuze zenze amanzi. The main enzyme - cytochrome c oxidoreductase oksijini.

Ubume kwisakhiwo yesine iquka cytochrome a, _3, kunye athom ezimbini zobhedu. Indima esembindini ukutshintshwa electron mpilo waya cytochrome _3. Ukusebenzisana kwezi ikumila kuthile zicinezelwa nitrogen benqanda kunye carbon monoxide, ngengqiqo lwehlabathi, oko kukhokelela ukupheliswa ATP amagama nentshabalalo.

ubiquinone

Ubiquinone - i-ezifana vitamin kweziyobisi, yikhompawundi lipophilic, leyo enambuzelayo ngokukhululekileyo Ebubanzini ndizayo. chain ayo zemiphunga akakwazi ukwenza ngaphandle esi sakhiwo, okt. k. Kuyinto kuzihlawulela electron evela kwizakhiwo I II ukuya kokunzima III.

Ubiquinone yi yemvelaphi benzoquinone. Esi sakhiwo kufuneka abhekisa kulo kwileta Schemes Q okanye LN olufinyeziweyo (ubiquinone lipophilic). Igcwala kwemolekyuli kukhokelela nokusekwa semiquinone - a oxidizer ngamandla, nto leyo eyingozi kwiseli.

ATP synthase

Indima ephambili ekubunjweni amandla bobabo kwi ATP-synthase. Esi sakhiwo isebenzisa amandla ngqo isindululo gribopodobnaya amasuntswana (protons) uyiguqula ibe amandla imichiza.

Inkqubo esisiseko eyenzeka kuyo njalo-njalo - i igcwala. I-chain yokuphefumla unoxanduva izithuthi electron kwi inwebu ayo ziyatyeba kunye nokwanda yabo matrix. Ngaxeshanye, izakhiwo mna, III kunye IV Impontshelwa protons hydrogen kwisithuba intermembrane. umahluko ndaziwisela emacaleni inwebu kukhokelela kwintshukumo zokukhomba of protons ngokusebenzisa ATP synthase. Ekubeni H + ngenisa isizalo, electron ziyafikeleleka (athe anxulunyaniswa oksijini) ukwenza into cala ukuba iseli - amanzi.

ATP synthase F0 siquka kunye subunits F1 leyo kunye zenze molecule umzila. F1 iqulathe ezintathu alpha beta subunits, nto leyo kunye zenze ijelo. Le siteshi kanye ubukhulu enye, nto leyo ibe protons hydrogen. Ngokuhamba amasuntswana kakuhle kuhlawuliswa ngokusebenzisa ATP synthase intloko F ₀ iimolekyuli ijijekileyo 360 degrees ngeenxa axis yayo. Ngeli xesha, ukuba AMP okanye ADP (adenozinmono- kunye diphosphate) ziya phosphate nikunyhashe eqhotyoshelweyo a iibhondi esinika amandla, nto leyo zingqonge isixa esikhulu wamandla.

ATP synthase zifumaneka emzimbeni, hayi nje kuphela kweli mitochondria. Kwizityalo, aba izakhiwo nazo zibekwe kwi-inwebu le vacuoles (tonoplast), kwakunye thylakoids chloroplast.

Kwakhona makanyebeleze iiseli kunye ATPases zezityalo akhoyo. Zinelungelo isakhiwo efanayo naleyo ye ATP synthase, kodwa inyathelo yabo ngqo kwi ukupheliswa zeentsalela phosphate ukuya inkcitho lwamandla.

Intsingiselo bemvelo chain sokuphefumla

Okokuqala, ukuphela imveliso etc reactions ngamanzi pathways ekuthiwa-(300-400 ml ngosuku). Okwesibini, intlaka yokuhlanganisa iminombo echumileyo ATP namandla ukugcina ndisezintanjeni kwemichiza kwemolekyuli. Usuku 40-60 kg adenosine iya kuhlanganiswa, yaye lowo lisetyenziswa ngayo iiseli enzymatic. Ubomi enye molecule ATP na umzuzu 1, ngoko ke chain sokuphefumla kufuneka zihambe, echanileyo ngaphandle iimpazamo. Kungenjalo, iseli uya kufa.

Mitochondria zithathwa izitishi ngamandla enye iseli. Inani labo kuxhomekeka amandla ezifunekayo kwimisebenzi ethile. Umzekelo, luvo nakubalwa ukuya ku-1000 mitochondria ezidla zakha cluster kwi kobuchopho-ebizwa ngokuba nophawu.

Umahluko phakathi chain yokuphefumla kwizityalo nezilwanyana

Xa izityalo, i "izityalo amandla" olongezelelweyo iseli a chloroplast. Ngomhla inwebu yangaphakathi zezi organelles nazo zifumaneka ATP synthase, yaye oku ingenelo phezu iiseli isilwanyana.

Kwakhona izityalo zingaphila kungomlinganiselo ophezulu carbon monoxide, nitrogen kunye benqanda ngenxa indlela benqanda-enganyangekiyo kwi NJL Ngoko chain yokuphefumla agcine ubiquinone, ukusuka apho electron zidluliselwa ngqo atom ioksijini. Ngenxa yoko, ngaphantsi ATP iya kuhlanganiswa, kunjalo, isityalo inokuphila iimeko ezingalunganga. Izilwanyana kwiimeko ezinjalo, sesichengeni elide ukuba afe.

Sinako ukuthelekisa nocikizeko nad, isininzi kunye indlela benqanda-enganyangekiyo ngokusebenzisa ATP Isalathisi ukwakhiwa xa betshintsha 1 electron.

• nge nad okanye NADP lisekwa iimolekyuli 3 ATP;
• Phisa kwakheka kunye iimolekyuli ezimbini ATP;
• of benqanda Iifomu 1 ezinzileyo indlela ATP mpilo.

ukubaluleka mvelo of etc

Ngokuba zonke izinto eukaryotic, umthombo enkulu wamandla ezidluliselwayo sokuphefumla. Eziphilayo ATP ezwi kwi iseli yahlulwe iintlobo ezimbini, zeendawana phosphorylation kunye oxidative phosphorylation. Etc lisetyenziswa Yindibanisela kuhlobo lwesibini lwamandla, okt. E. Ngenxa redox ngayo.

Xa eziphilayo prokaryotic ATP abunjwe kuphela zeendawana phosphorylation ku sigaba glycolysis. iiswekile carbon-emithandathu (kukhethwa glucose) inxaxheba kumjikelo reaction, kwaye iseli output ifumana molekyuli ezimbini ATP. Olu hlobo amandla ithathwa ukuba njini kakhulu nobu-, okt. K. Eukaryotes ngexesha phosphorylation oxidative wambumba 36 iimolekyuli ATP.

Noko ke, oku akuthethi ukuba izityalo namhlanje kunye nezilwanyana baye balahlekelwa ubuchule zeendawana phosphorylation. Nje olu hlobo ATP kuyondelelaniswe kuphela manqanaba amathathu imveliso yezamandla kwiseli.

Glycolysis kwi eukaryotes ithatha indawo kukho icytoplasm yeseli. Kukho zonke iienzymes eziyimfuneko ukuze anamathele glucose ukuba iimolekyuli ezimbini pyruvic acid ukwenza molekyuli 2 ATP. Onke amanyathelo ezilandelayo uthathe indawo kwi matrix ayo. umjikelo Krebs okanye ngomjikelo acid tricarboxylic, njengoko livela kwi-mitochondria. Oku ivaliwe reactions chain ngenxa apho nokulungelelanisa nad kunye zokunci- * H * H2. Ezi molekyuli ziya kusetyenziswa consumable in NJL