Imolekyuli Yehemoglobin Edalwe Ngokungummangaliso

“Ukuphefumla kubonakala kuyeyona nto yakha yalula, kodwa le nto buxhomekeke kuyo ubomi ixhomekeke ekusebenzisaneni kweendidi ezininzi zamasuntswana emolekyuli enkulu nentsokothileyo.”—UMax F. Perutz, omnye wabantu abafumana iMbasa kaNobel ngowe-1962 ngenxa yohlolisiso lwakhe lwemolekyuli yehemoglobin.

UKUPHEFUMLA—ayikho enye into engokwemvelo ngaphezu kwaleyo. Bambalwa kuthi abakhe bacingisisa ngayo. Kodwa ke, ukuphefumla bekungenakusinceda nganto ukuba imolekyuli yehemoglobin, imolekyuli entsonkothileyo edalwe nguMdali wethu, ibingekho. Ihemoglobin engaphakathi kweeseli ezibomvu eziziitriliyon ezingama-30 idlulisela ioksijini esuka kwimiphunga iyise emzimbeni wonke. Ukuba ibingekho ihemoglobin, besiya kufa ngoko nangoko.

Iimolekyuli zehemoglobin zikwazi njani ukuthatha iimolekyuli zeoksijini, zizigcine de kufike ixesha elifanelekileyo zize zizidlulisele ngexesha elililo? Zincedwa bubuchule obumangalisayo obugqitha oboononjineli.

“Iimoto” Ezincinane Ezenziwe Ngemolekyuli

Imolekyuli nganye yehemoglobin ekwiseli unokuyifanisa nemoto encinane eneminyango emine, ekunokukhwela kuyo “abantu” abane kuphela. Le moto iyimolekyuli ayifuni mqhubi kuba ihamba ngaphakathi kweseli ebomvu yegazi ezaliswe ziimolekyuli zehemoglobin.

Uhambo lwemolekyuli yehemoglobin luqala xa iiseli ezibomvu zegazi zifika emingxunyeni yemiphunga. Njengokuba singenisa umoya emiphungeni yethu, iimolekyuli zeoksijini ezingenayo zikhangela indlela yokufika kwimiphunga. Ezi molekyuli ziye zidibane neeseli ezibomvu zegazi. Kwiseli nganye iingcango zemoto ihemoglobin ziyavaleka. Noko ke, ngokukhawuleza imolekyuli yeoksijini izinyanzela kule moto yehemoglobin.

Ngoku kwenzeka into ebangel’ umdla. Xa iphakathi kwiseli ebomvu imolekyuli yehemoglobin itshintsha ubume bayo. Yomine “iminyango” yale moto yehemoglobin iqalisa ukuvuleka njengoko kungena iimolekyuli zokuqala zeoksijini zize ezinye zingene lula. Le nkqubo ibizwa ngokuba kukusebenzisana isebenza kakuhle kangangokuba xa umntu ephefumla ama-95 ekhulwini azo zonke iimolekyuli zehemoglobin ezikwiiseli ezibomvu zizaliswa yioksijini. Iimolekyuli zehemoglobin eziyikota yebhiliyon kwiseli nganye zinokuba neemolekyuli zeoksijini eziyibhiliyon. Kungekudala ezi seli zibomvu zegazi ezinezi moto zithutha le oksijini ziyise emzimbeni wonke. Kodwa kusenokwenzeka ukuba uyazibuza, ‘Yintoni enqanda ioksijini ukuba ingaphumi ngaphambi kwexesha?’

Impendulo kukuba phakathi kwemolekyuli nganye yehemoglobin iimolekyuli zeoksijini zithi nca kwiiathom zeiron. Mhlawumbi ukhe wayibona into eyenzekayo xa kudibana ioksijini neiron emanzini. Kudla ngokuvela irusi. Xa i-iron irusa ioksijini ivaleleka kwikristale. Ngoko imolekyuli yehemoglobin ikwazi njani ukudibanisa i-iron neoksijini iphinde izahlukanise kwiiseli ezibomvu zegazi ezingamanzi ngaphandle kokuvelisa irusi?

Ukuyihlolisisa

Ukuze siphendule loo mbuzo, makhe sihlolisise imolekyuli yehemoglobin. Yenziwe ngeeathom ezingama-10 000 zehydrogen, icarbon, initrogen, isulfur neoksijini ezijikeleze iiathom ezine zeiron. Yintoni ebangela ukuba ezi athom zine zeiron zifune inkxaso engaka?

Okokuqala, ezi athom zine zeiron zinombane, ngoko kufuneka zilawulwe. Iiathom ezinombane ezibizwa ngokuba zii-ion zinokwenza umonakalo kwiiseli xa ziyekiwe zazihambela nje. Ezi ion zeiron zine zibanjwe ziipleyiti eziqinileyo.a Okwesibini, ezi pleyiti zine zibekwe kakuhle kwimolekyuli yehemoglobin ngendlela enceda iimolekyuli zeoksijini zikwazi ukufikelela kwii-ion zeiron kodwa iimolekyuli zamanzi zingakwazi. Xa engekho amanzi irusi ayiveli.

I-iron iyodwa ekwimolekyuli yehemoglobin ayikwazi ukudibana neoksijini ize izahlule kuyo. Kodwa ukuba ezi athom zeiron zine bezingekho imolekyuli yehemoglobin ibingayi kunceda nganto. Kuxa ezi ion zeiron zifakwe kwimolekyuli yehemoglobin apho ioksijini inokudluliselwa egazini lonke.

Ukukhupha Ioksijini

Njengokuba iseli ebomvu ishiya imithambo edlulisela igazi ize iye kwezinye iindawo emzimbeni iyatshintsha imeko yeseli ebomvu yegazi. Umzimba ushushu kunakwimiphunga yaye kukho ioksijini encinane neasidi eninzi ngenxa yokubakho kwecarbon dioxide. Xa kunje iimolekyuli zehemoglobin ezikwiseli ziyazi ukuba sele kulixesha lokukhupha ioksijini.

Xa iimolekyuli zeoksijini ziphuma kwimolekyuli yehemoglobin ziyatshintsha kwakhona. Olu tshintsho lunceda ukuba iimolekyuli zehemoglobin zivale zize zishiye ioksijini ngaphandle. Oku kunceda ukuba ihemoglobin ingabuyiseli ioksijini kwimiphunga. Kunoko, ibuya necarbon dioxide.

Kungekudala ezi seli zibomvu zegazi zingenaoksijini zibuyela kwimiphunga apho iimolekyuli zehemoglobin zikhupha icarbon dioxide zize zifumane ioksijini engakumbi—nto leyo ephindaphindeka kangangamawakawaka ebudeni bobomi beseli ebomvu yegazi ephila malunga neentsuku ezili-120.

Izicacele into yokuba ihemoglobin ayifani nezinye iimolekyuli eziqhelekileyo. “Yimolekyuli enkulu nentsokothileyo” njengokuba kubonisiwe ekuqaleni kweli nqaku. Ngokuqinisekileyo sinombulelo kuMdali wethu yaye siyamangaliswa yindlela ekrelekrele asidale ngayo.

[Umbhalo osemazantsi]

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NYAMEKELA IHEMOGLOBIN ESEMZIMBENI WAKHO!

Xa abantu besithi igazi lakho alinairon yaneleyo enyanisweni batheth’ ukuthi ligazi elingenahemoglobin yaneleyo. Ukuba ezi athom zeiron zine bezingekho, ezinye iiathom zemolekyuli ezili-10 000 bezingayi kunceda nganto. Ngoko kubalulekile ukufumana i-iron eyaneleyo ngokutya ukutya okunesondlo. Ezinye iindlela zokufumana i-iron zidweliswe kwisicangca esikweli nqaku.

Ngaphezu kokutya ukutya okuneiron sifanele sisebenzise la macebiso: 1. Yenza umthambo rhoqo. 2. Musa ukutshaya. 3. Musa ukuhlala nabantu abatshayayo. Yintoni ebangela ukuba icuba libe yingozi?

Kungenxa yokuba umsi wecuba unecarbon monoxide, ufana nqwa nomsi ophuma emotweni. Icarbon monoxide ingunobangela weengozi ezibulalayo yaye idla ngokusetyenziswa ngabantu abaninzi abafuna ukuzibulala. Icarbon monoxide ithi nca kwiiathom zeiron ekwihemoglobin ngokuphindaphindwe kangangama-200 kuneoksijini. Ngoko ke, umsi wecuba uyamtyhefa umntu ngokunqanda ioksijini ingangeni emzimbeni.

[Isicangca]

UKUTYA UBUNGAKANANI I-IRON(mg)

Iiblackstrap molasse icephe elinye 5.0

Itofu ekrwada isiqingatha sekomityi 4.0

Iintlumayo isiqingatha sekomityi 3.3

Inyama yenkomo iigram ezingama-85 3.2

Iipesika ezomisiweyo ezimbini nesiqingatha 2.6

Iimbotyi ezinombala omdaka isiqingatha sekomityi 2.6

Iwheat germ ikota yekomityi 2.6

Iiertyisi isiqingatha sekomityi 2.4

Ibroccoli udiza lube lunye 2.1

Inyama yekarikuni iigram ezingama-85 2.0

Isipinatshi ikomityi yaso sikrwada 0.8

[Umzobo/Umfanekiso okwiphepha 26]

(Ukuba ufuna inkcazelo ehlahlelwe kakuhle, yiya kwimpapasho)

Inxalenye yehemoglobin eyenziwe ngeprotini

Ioksijini

Iiathom ze-iron

IHeme

Kwimiphunga ezaliswe yioksijini, imolekyuli yeoksijini ithi nca kwihemoglobin

Emva kokuba kudibane imolekyuli yeoksijini yokuqala, ihemoglobin itshintsha ubume bayo nto leyo evumela ezinye iimolekyuli zeoksijini ezintathu zithi nca kuyo

Ihemoglobin ithatha iimolekyuli zeoksijini kwimiphunga ize izidlulisele emzimbeni