Enzyme catalase: Izici eziyinhloko

Catalase - enzyme wathola eziphilayo ezitholakala cishe yonke ophilayo. Umsebenzi wayo main - catalyze noqhekeko we-hydrogen peroxide ku izinto ayinangozi ngoba umzimba. Catalase kubaluleke kakhulu ngenxa yokuphila amaseli, njengoba uwuvikela ukubhujiswa ngokusetshenziswa esisheshayo zinhlobo oksijini.

Uhlolojikelele

Enzyme catalase iphathelene oxidoreductase - ekilasini ebanzi enzyme ukuthi catalyze nokudluliswa electron kusukela ekunciphiseni-molecule (onikelayo) ukuze i-molecule ye oxidant (acceptor).

PH elikhulu catalase emzimbeni womuntu imayelana 7 Nokho, izinga yokusabela ayishintshi kakhulu ngesikhathi abakuzuzile Inkomba hydrogen kusuka 6.8 kuya 7.5. I elikhulu pH yezinye catalases ezisukela 4 kuya ku-11, kuye ngokuthi uhlobo umzimba. Amazinga elikhulu ubuye ezahlukene ngoba umuntu mayelana 37 ^° C

Catalase - omunye enzyme esheshayo. i-molecule elilodwa kuphela okwazi zokuguqula izigidi yayo molecule i-hydrogen peroxide namanzi ne-oksijini ngomzuzwana. Ngokuya enzymology okusho ukuthi inani elikhulu linemibhikisho nobuntu enzyme catalase.

Ukwakheka enzyme

Catalase kuyinto tetramer ka polypeptide ngamaketanga ezine, ngasinye zazo has kuka-500 nama-amino acid ubude. Enzyme yakhiwa amaqembu ezine heme porphyry, futhi lapho ihlangana asebenzayo zinhlobo oksijini. I oxidized heme wokufakelwa iqembu catalase.

Umlando yokutholakala

Catalase ayikaziwa ukuba ososayensi eminyakeni 1818 kuze Louis Jacques Thénard wemithi zatholakala e amaseli i-hydrogen peroxide ophilayo akuyona wasikisela ukuthi ukubhujiswa kwalo ngenxa isenzo i material engaziwa begazi.

Ngo-1900, wemithi German, u-Oskar Leo wokuqala wethula "catalase" igama elibhekisela kuso oyimfihlakalo izidakamizwa ukubola peroxide. Wakwazi ukuphendula umbuzo, lapho enzyme catalase equkethwe. Ngenxa yalokho zokuhlolwa eziningi Oskar Leo embula ukuthi lesi enzyme kuyisici sobuntu cishe zonke izilwane nezitshalo. Emangqamuzaneni aphilayo, kanye nezinye enzyme eziningi, catalase kuqukethwe peroxisomes.

Ngo-1937 yena waba ngowokuqala crystallize catalase kusuka yenkomo isibindi. 250 KD - isisindo yamangqamuzana enzyme wamiswa ngo-1938. Ngo-1981 ososayensi baye bathola izithombe isakhiwo ezintathu-ntathu of sezinkomo catalase.

I catalysis ka-hydrogen peroxide

Naphezu kweqiniso lokuthi i-hydrogen peroxide - umkhiqizo evamile umzimba izinqubo eziningi, akusiyo ingozi emzimbeni.

Ukuvimbela ukubhujiswa kwamangqamuzana nezicubu, i-hydrogen peroxide kumele ngokushesha ibe nezinye, kancane kuyingozi emzimbeni. Kuyinto lenselelo futhi ubhekana enzyme catalase - sekubola le peroxide ezimbili molecule molecule yamanzi bese izinhlayiya zomoya-mpilo.

Basabela kanjani i-hydrogen peroxide noqhekeko ezintweni eziphilayo:

2 H ₂ O ₂ → 2 H ₂ O + O ₂

Mshini yamangqamuzana enzyme cleavage ka-hydrogen peroxide ngu catalase ayikahlanganiswa ncamashi waqonda. Kusolwa ukuthi ukusabela senzeka ngezigaba ezimbili - esigabeni sokuqala ehlanganisa yensimbi catalase iqembu wokufakelwa banamathele athomu-mpilo we peroxide, lokhu yakha eyodwa molecule yamanzi. In the isinyathelo wesibili heme oxidized uxhumana nolunye molecule i-hydrogen peroxide, kanjalo ukwakha enye i-molecule yamanzi bese omunye molecule umoya-mpilo.

Ngalesi senzo of enzyme catalase ngokuba peroxide hydrogen, khona ketshezi asebenzayo zezinhlobo izicubu kunqunywa kalula. Ukuze lokhu ukwengeza ngokwanele ukuba isivivinyo sampula esincane i-hydrogen peroxide kanye abheke ukusabela. Ukuba khona enzyme ekutshela kumiswa-mpilo Bubbles. Cishe le ndlela yokusabela ezinhle ngoba Akudingi amathuluzi noma imishini ekhethekile - kungabonwa ngeso lenyama.

Kuyaphawuleka ukuthi i-ion kwanoma iyiphi heavy metal ingaba njengesihluthulelo inhibitor noncompetitive ka catalase. Ngaphezu kwalokho, bonke cyanide eyaziwa liziphatha njengoba inhibitor ukuncintisana catalase, uma ezicutshini eziningi i-hydrogen peroxide. Arsenates ukwenza njenge activators.

isicelo

Isenzo of enzyme catalase ubola hydrogen peroxide isetshenzisiwe embonini yezokudla - ngokusebenzisa le enzayimu esuswa ubisi H ₂ O ₂ ukulungiswa ushizi. Olunye uhlelo lokusebenza - ukudla emabhokisini ezikhethekile evikela umkhiqizo ngokumelene namachibi. Catalase liyasetshenziswa basembonini yendwangu yokususa hydrogen peroxide ngendwangu.

It is lisetshenziswe inhlanzeko contact lens izinto eziningi ezincane. Ezinye izibulali-magciwane yakhiwa i-hydrogen peroxide kanye catalase isetshenziswa ekuhlukaniseni leli ingxenye ngaphambi usebenzise lens.

umsebenzi

Umsebenzi we catalase enzyme incike yobudala umzimba. Kwezicubu abasha yomsebenzi enzyme lingaphezulu kakhulu kunezinye ubudala. Nge yobudala abantu futhi izilwane umsebenzi catalase kancane kancane kunciphisa ngenxa yokuguga kwezicubu eziyishumi nemitshingo.

Ngokocwaningo yamuva, ukwehla womsebenzi catalase ingenye izimbangela izinwele graying. Hydrogen peroxide ikhiqizwa ngokuqhubekayo emzimbeni womuntu, kodwa akukho umonakalo - catalase ubola ngokushesha. Kodwa uma ezingeni le enzayimu kuyehla, kusobala ukuthi akuyona yonke le peroxide hydrogen is catalyzed ngu enzyme. Ngakho, ke discolors ngaphakathi izinwele by Ukuqedwa udayi yemvelo. Ukutholakala kwaleli qiniso ezingalindelekile okwamanje ihlolwa abacwaningi, futhi kungaba neqhaza ekuthuthukiseni izidakamizwa asimise graying izinwele.