Inyandiko
Ubururu bwa metilene na vitamini C: impamvu umuti ushobora kutagira ibara
Ushyira ikinini cya vitamini C mu kirahuri cy'umuti w'ubururu bwa metilene, ukavanga, ukareba uko ibara ry'ubururu rigenda rishira. Nyuma y'umunota, uwo muti uba usa n'amazi asanzwe. Biroroshye guhita wumva ko vitamini C yashenye iryo rangi cyangwa yaribujije kugira icyo rikora.
Iyo myumvire si yo, kandi iryo kosa rifite icyo rivuze. Icyo urimo kureba ni ihinduka ry'urwego rwa okisidasiyo rishobora gusubira inyuma, si ugusenyuka. Irangi riracyahari. Iyo ibisabwa byujujwe, ibara riragaruka.
Imimerere ibiri y'irangi
Ubururu bwa metilene bugira imimerere ibiri izwi neza. Imimerere yatakaje elegitoroni, akenshi yandikwa MB+, ifite urusobe rwagutse rw'impeta zifite amasano akurikirana, rwinjiza cyane urumuri rufite uburebure bw'umuraba buri hafi ya 664 nm. Uko kwinjiza urumuri ni ko gutanga ibara ry'ubururu. Imimerere yahawe elegitoroni, leyukometilene (LMB), ntikigira uwo murongo ukomeye wo kwinjiza urumuri rugaragara, bityo umuti utagizwe n'irangi ryinshi ugasa n'utagira ibara.
Tekereza kuri iryo rangi nk'ububiko buto bwa elegitoroni bushobora kongera kuzuzwa. Kuryongeramo elegitoroni na porotoni bituma ritakaza ibara. Kurikuramo izo elegitoroni bituma ibara rigaruka:
MB+ + H+ + 2e- bihinduka LMB (itagira ibara)
Vitamini C ni yo itanga izo elegitoroni. Askorubate igenda itakaza elegitoroni ihinduka dehidiroaskorubate, igatanga ubushobozi bwo gutanga elegitoroni ebyiri; bityo mu ibarura ryoroshye ry'ubwo butabire, moli imwe ya askorubate iha elegitoroni hafi moli imwe ya MB+. Mu miti nyakuri ikoreshwa muri laboratwari, iryo barura riragorana kurushaho kuko ogisijeni yashonze mu muti na yo ihatanira izo elegitoroni. Ni yo mpamvu akenshi hakenerwa askorubate irenze igipimo cy'ibanze kugira ngo umuti ukomeze kutagira ibara.
Uko ibyo bibaho si ngombwa ko biba intambwe imwe gusa itanga elegitoroni ebyiri. Radikali n'ibinyabutabire byo hagati byahawe igice cya elegitoroni na byo bigira uruhare, kandi inzira nyayo ihinduka bitewe n'igishongeshi, ubukari n'ubwinshi bw'ibinyabutabire mu muti. Ariko igisubizo cya nyuma ni kimwe. MB+ y'ubururu ihinduka LMB itagira ibara, kandi vitamini C irakoreshwa muri icyo gikorwa.
Impamvu kunyeganyeza bituma ubururu bugaruka
Uburyo busanzwe bwo gukora iri gerageza mu ishuri bugira igice cya kabiri. Iyo uretse agacupa karimo umuti utagira ibara katanyeganyega, ukomeza kutagira ibara. Iyo ukanyeganyeje, ubururu buragaruka. Iyo utegereje, ibara rirongera rigashira.
Igisubiza ibara ni ogisijeni. O2 yashonze mu muti ituma LMB itakaza elegitoroni ikongera kuba MB+; bityo kunyeganyeza ntibikangura irangi. Ahubwo byongera ogisijeni yashonze mu muti, kuko bivanga umwuka uri mu mwanya wo hejuru y'umuti n'uwo muti, bigatuma ihinduka risubira inyuma ryihuta. Igihe cyose hakiri askorubate isigaye, MB+ yongeye kuboneka ihabwa elegitoroni na none. Ibyo bituma habaho uru ruziga ruzwi: kuruhuka bituma umuti utagira ibara, kunyeganyeza bituma uba ubururu, gutegereza bikongera kuwugira utagira ibara. Iyo askorubate imaze gushira, ogisijeni iratsinda burundu, umuti ugakomeza kuba ubururu.
Ni yo mpamvu imyerekano y'ubururu bwa metilene na vitamini C iterwa n'imiterere y'igikoresho gikoreshwa. Agakoresho gapfundikiye ko gupimiramo urumuri, gafite umwanya muto w'umwuka hejuru y'umuti, gatuma umuti ukomeza kutagira ibara igihe kirekire kurusha ikirahuri cya laboratwari kigari. Kwinjizamo umwuka mwinshi bigabanya igihe umuti umara utagira ibara. Bityo umuntu wese utanga raporo y'iri gerageza agomba kuvuga uko ogisijeni yari imeze, aho kuvuga gusa ingano z'ibinyabutabire byakoreshejwe.
Imyerekano igenzuwe n'ibisabwa kugira ngo ikorwe
Ifoto ibanza y'iyi nyandiko yerekana igereranya rigamijwe: icyitegererezo ngenzura cya MB+ y'ubururu iruhande rw'icyitegererezo cya LMB cyahawe elegitoroni na askorubate, byombi biri mu rumuri rumwe. Kugira ngo igisubizo gishobore kongera kuboneka, genzura buri kintu gihindura umuvuduko w'ihinduka:
| Ikintu gihinduka | Uko gisabwa kuba kimeze | Impamvu ari ingenzi |
|---|---|---|
| Ubururu bwa metilene | 10 kugeza kuri 90 micromolar mu muti wa fosifate ugenzura pH, pH 7 | Bihuye n'ubwinshi bwakoreshejwe mu bushakashatsi bwa redox bwatangajwe kandi bigatuma kwinjiza urumuri kuguma mu rugero rupimika |
| Askorubate | 1 mM ya askorubate ya sodiyumu, iteguwe ako kanya | Itanga ubushobozi buhagije bwo gutanga elegitoroni kugira ngo ibara rishire burundu |
| Umuti ugenzura pH na pH | 50 mM ya fosifate, pH 7.0, ubushyuhe bwo mu cyumba | Bigena imimerere ya askorubate n'ukudapfa guhinduka kwa LMB |
| Urumuri | Urumuri ruke rwo mu cyumba, wandike igihe umuti warumazemo | Urumuri rukomeye rwongeramo inzira za redox ziterwa n'urumuri n'izibyara perogiside |
| Ogisijeni | Agacupa kamwe kuzuye ogisijeni iva mu mwuka, akandi kanyujijwemo azote kugira ngo ikuremo ogisijeni | Bitandukanya uruziga rwa redox rutagira izindi nzira ziruvangamo no kongera gutakaza elegitoroni |
| Ibyuma | Ibinyabutabire byo ku rwego rw'isesengura, hamwe n'icyitegererezo ngenzura kimwe kirimo ikinyabutabire gifata iyoni z'ibyuma | Icyuma kiri mu rugero ruto cyane gifungura inzira y'ubutabire bwa Fenton (reba hepfo) |
Fata amafoto y'utwo ducupa twombi mu bihe byagenwe, urugero ku minota 0, 1, 5, na 15, hanyuma utunyeganyeze wongere ufate amafoto. Agacupa kanyujijwemo azote kagomba kumara igihe kirekire kurusha akandi katagira ibara. Agacupa kinjijwemo umwuka kagomba gusubirana ubururu vuba nyuma yo kunyeganyezwa. Niba icyitegererezo kitongera kuba ubururu na rimwe, ndetse n'iyo kinyeganyejwe kandi kinjijwemo umwuka, tekereza ko hashobora kuba habaye ugusenyuka kudashobora gusubira inyuma, aho kuba uguhabwa elegitoroni gusa.
Abategura imvange bakoresha iyi mitekerereze no ku rugero runini. Uko ubururu bwa metilene bwitwara mu ruvange biterwa n'imiterere yose ya redox n'ibigize urwo ruvange. Mu igerageza ryo kureba niba umuti udapfa guhinduka, hagomba kwandikwa pH, ogisijeni yashonze mu muti, ingano y'urumuri rwawugezeho n'ibyuma biri mu rugero ruto cyane, hamwe n'ibara ryagaragaye.
pH, urumuri n'ubwinshi bw'ibinyabutabire bigira ingaruka zitandukanye
Abagitangira akenshi babaza niba aside cyangwa baze byihutisha ihinduka. Igisubizo nyacyo ni uko pH igira ingaruka ku bice bibiri bitandukanye by'uruziga. Mu muti w'amazi urimo aside, kuboneka kwa porotoni bishobora kwihutisha intambwe askorubate ihamo MB+ elegitoroni. Ariko LMB ubwayo irushaho kwihanganira gutakaza elegitoroni bitewe n'umwuka iyo iri muri aside, kandi yongera kuzitakaza vuba cyane uko pH izamuka. Bityo icyitegererezo kirimo aside gishobora gutakaza ibara vuba kigakomeza kutagira ibara, naho icyitegererezo kirimo baze kigatakaza ibara kikanasubirana ubururu vuba. Ibyo byombi ni ukuri mu mimerere yabyo.
Urumuri rwongeramo indi nzira. Ubururu bwa metilene bwahawe ingufu n'urumuri bugera mu mimerere ya triplet imara igihe kirekire, ibamo ihererekanya rya elegitoroni hamwe na askorubate na ogisijeni. Ubwo butabire buterwa n'urumuri bushobora kwihutisha gushira kw'ibara, kurigarura cyangwa kubyara ibinyabutabire bya ogisijeni byihutira kwitwara, bitewe n'uburebure bw'umuraba w'urumuri, urwego rwa ogisijeni n'ubwinshi bw'ibinyabutabire mu muti. Fata urumuri nk'ikintu gihinduka mu igerageza kandi wandike uko rwakoreshejwe.
Ubwinshi bw'ibinyabutabire mu muti ni bwo bugena inzira itsinda. Askorubate nyinshi ituma ibara rishira vuba kandi hakabaho inshuro nyinshi zo kunyeganyeza ibara rikagaruka hanyuma rigashira. Irangi ryinshi risaba ubushobozi bwo gutanga elegitoroni bwiyongera ku rugero rumwe. Ogisijeni nyinshi yashonze mu muti ituma ubururu bwiganza. Iyo irangi ari ryinshi cyane mu muti, hiyongeraho indi ngorane kuko molekile z'ubururu bwa metilene zifatanya zikaba amatsinda ya molekile ebyiri cyangwa amatsinda manini, afite imiterere yo kwinjiza urumuri yahindutse. Bityo gukuba irangi kabiri ntibiba bikigwiza kabiri imyitwarire imwe.
Ese vitamini C ibuza ubururu bwa metilene kugira icyo bukora?
Iki ni cyo kibazo kiri inyuma y'ishakisha ryinshi ryerekeye ubururu bwa metilene na vitamini C, kandi gikeneye igisubizo nyacyo. Oya, gushira kw'ibara ntibivuze ko irangi ritakigira icyo rikora. Igice cya molekile gitanga ibara cyahinduye imimerere, ariko igice shingiro cya fenotiyazine n'ubushobozi bwacyo bwo kugira uruhare muri redox bikomeza kuba mu muti. Iryo hinduka rishobora gusubizwa inyuma n'umwuka, kandi imimerere yahawe elegitoroni na yo ishobora kugira icyo ikora: LMB nta muriro w'amashanyarazi ifite kandi ikunda ibinure kurusha MB+. Mu bushakashatsi ku ngirabuzimafatizo, yambuka utwugara twazo mbere yo kongera gutakaza elegitoroni imbere muri zo.
Ubushakashatsi ku ngirabuzimafatizo burabigaragaza neza. Mu ngirabuzimafatizo z'urukuta rw'imbere rw'imiyoboro y'amaraso zororewe muri laboratwari, ubururu bwa metilene buri mu rugero ruto rwa micromolar bwongera ibikorwa by'inzira ya pentose fosifate, ari na ko butuma NADPH na NADH bitakaza elegitoroni. Iyo burenze hafi 5 micromolar, bwongera ibipimo by'ibinyabutabire bituma ibindi bitakaza elegitoroni imbere mu ngirabuzimafatizo igihe nta nkunga ya gilukoze ihari. Ingirabuzimafatizo zahawe askorubate nyinshi zigenda zituma iyo askorubate itakaza elegitoroni iyo zihuye n'irangi, kandi iyo askorubate igabanya gusa igice cy'ikimenyetso cy'ibinyabutabire bituma ibindi bitakaza elegitoroni, nk'uko byatangajwe mu bushakashatsi kuri redox y'irangi mu ngirabuzimafatizo z'urukuta rw'imbere rw'imiyoboro y'amaraso. Mu yandi magambo, askorubate igira uruhare mu ihererekanya rya elegitoroni muri redox. Ntiyambura irangi ubushobozi bwo kugira icyo rikora.
Urumuri rutuma ibyo birushaho kugaragara. Iyo imvange z'ubururu bwa metilene, askorubate na ogisijeni zigezeho urumuri, zikoresha ogisijeni, zikagwiza perogiside ya hidirojeni, kandi iyo hari icyuma gikora nk'umusemburo, zikabyara radikali ya hidirogisile binyuze mu butabire bwa Fenton. Ibyo byagaragajwe n'amagerageza yo gufata radikali no gupima ikoreshwa rya ogisijeni. Radikali za hidirogisile zishobora kwangiza molekile z'ibinyabuzima ku buryo budashobora gusubira inyuma, zikanasenya irangi ubwaryo. Bityo icyitegererezo cyatakaje ibara burundu kiri mu rumuri kandi cyandujwe n'icyuma ntikiba kigaragaza uguhabwa elegitoroni kutavangiwe n'izindi nzira. Gishobora kuba kigaragaza ugusenyuka guterwa n'ubutabire bwo ku ruhande.
Ibyo umuti utagira ibara utagaragaza
Hari imyanzuro itatu ikunze gufatwa irenze ibimenyetso bihari, kandi ikwiye kwirindwa mu nyandiko za laboratwari, ku birango no ku mapaji yerekanywa mu kwigisha.
Icya mbere, kutagira ibara ntibivuze kutagira ingaruka mbi. LMB hamwe na ogisijeni n'ibyuma biri mu rugero ruto cyane bishobora gushyigikira inzira zibyara perogiside na radikali, cyane cyane mu rumuri. Kwemeza ko nta ngaruka mbi zihari bisaba ubushakashatsi ku burozi, si ugupima ibara.
Icya kabiri, kutagira ibara ntibivuze ko umwanda wavanyweho. Irangi n'ibinyabutabire bifatanya na ryo muri redox biracyahari. Ibimenetse, amazi asohoka mu bikorwa n'ibikoresho byandujwe n'irangi ntibisukurwa no kongeramo askorubate. Hakenewe kubyemeza hakoreshejwe isesengura, ingingo ivugwaho mu buryo bwo gupima ibisigazwa no kugenzura iyivanwaho ry'umwanda.
Icya gatatu, kutagira ibara ntibigaragaza uburyo bw'ingirakamaro bwo gukoresha ibyo binyabutabire byombi hamwe. Ihinduka ribera mu muyoboro w'igerageza ntacyo rivuga ku kwinjizwa mu mubiri, gukwirakwizwa mu ngingo, ingano ikoreshwa cyangwa umutekano w'imikoranire yabyo mu bantu. Umuntu wese utekereza kubihuza agamije ubuzima akwiye kubanza gusoma ubushakashatsi ku mikoranire n'umutekano wabyo, akagisha inama inkomoko zibifitiye ubumenyi aho gushingira ku bibera mu gacupa.
Ibisobanuro nyabyo bigarukira ku bintu bike, ariko bifite akamaro kurushaho. Ubururu bwa metilene hamwe na askorubate ni icyitegererezo cyoroheje cy'uruziga rwa redox: vitamini C itanga elegitoroni, irangi rigatakaza ibara, ogisijeni ikakira izo elegitoroni, ibara rikagaruka, naho urumuri, pH, ubwinshi bw'ibinyabutabire n'icyuma bikagena umuvuduko n'ibindi bikomoka kuri iryo hinduka. Iyo icyo gitekerezo kimaze kumvikana, imyerekano ireka kuba amayeri igahinduka uburyo bwo kumenya ibiri kuba. Niba icyitegererezo cyawe cyitwara ukundi, banza ugenzure uko ogisijeni ikigeraho, ingano y'urumuri rwakigezeho, pH n'ukwanduzwa n'ibyuma mbere yo gushidikanya ku irangi.