I-Hemoglobin (Hb) iyi-metalloprotein equkethe insimbi etholakala ngobuningi emangqamuzaneni abomvu egazi cishe azo zonke izilwane ezinomgogodla. Ivame ukubizwa ngokuthi “i-molecule esekela ukuphila” ngendima yayo ebalulekile ekuphefumuleni. Le phrotheni eyinkimbinkimbi inesibopho somsebenzi obalulekile wokuthutha umoya-mpilo usuka emaphashini uye kuzo zonke izicubu emzimbeni kanye nokwenza kube lula ukubuya kwe-carbon dioxide ukuze ikhishwe. Ukuqonda umsebenzi wayo, izindlela ezinhle ezilawula ukuziphatha kwayo, kanye nokubaluleka okukhulu kokulinganisa kwayo kwezokwelapha kunikeza ithuba lokuthola impilo yabantu kanye nezifo.

Umsebenzi kanye Nendlela Yokusebenza: Ubuciko Bobunjiniyela Bama-Molecular

Umsebenzi oyinhloko we-hemoglobin ukuthuthwa kwegesi. Kodwa-ke, ayiwenzi lo msebenzi njengesiponji esilula nesingenamsebenzi. Ukusebenza kahle kwayo kuvela ekwakhiweni kwesakhiwo okuyinkimbinkimbi kanye nezindlela zokulawula ezinamandla.

Isakhiwo Sama-Molecular: I-Hemoglobin iyi-tetramer, eyakhiwe ngamaketanga amane e-globin protein (ama-alpha amabili nama-beta amabili kubantu abadala). Iketanga ngalinye lihlotshaniswa neqembu le-heme, isakhiwo sendandatho esiyinkimbinkimbi esine-athomu yensimbi ephakathi (i-Fe²⁺). Le athomu yensimbi iyindawo yangempela yokubopha i-molecule ye-oxygen (O₂). Ngakho-ke i-molecule eyodwa ye-hemoglobin ingathwala ama-molecule amane e-oxygen.

Ukubopha Ngokubambisana kanye neSigmoidal Curve: Lokhu kuyitshe elibalulekile ekusebenzeni kahle kwe-hemoglobin. Lapho i-molecule yokuqala ye-oxygen ibopha eqenjini le-heme emaphashini (lapho ukugcwala kwe-oxygen kuphezulu khona), kubangela ushintsho lokwakheka kwesakhiwo se-hemoglobin yonke. Lolu shintsho lwenza kube lula ngama-molecule amabili e-oxygen alandelayo ukubopha. I-molecule yesine yokugcina ye-oxygen ibopha kalula kakhulu. Lokhu kuxhumana "okubambisanayo" kuphumela ku-characteristic sigmoidal (shaped-shaped) oxygen dissociation curve. Lobu buhlobo be-S bubalulekile—kusho ukuthi endaweni yamaphaphu ecebile nge-oxygen, i-hemoglobin igcwala ngokushesha, kodwa ezicutshini ezingenawo umoya-mpilo, ingakhipha inani elikhulu le-oxygen ngokuncipha okuncane kwengcindezi.

Ukulawulwa kwe-Allosteric: Ukusondelana kwe-hemoglobin nomoya-mpilo akukaguquki; kulungiswa kahle yizidingo ze-metabolic zezicubu. Lokhu kufezwa ngama-allosteric effectors:

Umphumela we-Bohr: Ezicutshini ezisebenzayo, umsebenzi ophezulu we-metabolic ukhiqiza i-carbon dioxide (CO₂) kanye ne-asidi (H⁺ ions). I-hemoglobin izwa le ndawo yamakhemikhali futhi isabela ngokunciphisa ukuthambekela kwayo komoya-mpilo, okubangela ukukhishwa okukhulu kwe-O₂ lapho idingeka khona kakhulu.

I-2,3-Bisphosphoglycerate (2,3-BPG): Le nhlanganisela, ekhiqizwa kumaseli abomvu egazi, ibopha i-hemoglobin futhi izinzise isimo sayo sokungabi nomoya-mpilo, ikhuthaze kakhulu ukukhishwa komoya-mpilo. Amazinga e-2,3-BPG ayanda ezimweni ezingapheli ze-hypoxia, njengasezindaweni eziphakeme, ukuze kuthuthukiswe ukulethwa komoya-mpilo.

Ukuthuthwa kwe-Carbon Dioxide: I-Hemoglobin nayo idlala indima ebalulekile ekuthuthweni kwe-CO₂. Ingxenye encane kodwa ebalulekile ye-CO₂ibopha ngqo kumaketanga e-globin, yakha i-carbaminohemoglobin. Ngaphezu kwalokho, ngokubopha ama-H⁺ion, i-hemoglobin yenza kube lula ukuthuthwa kweningi le-CO₂ njenge-bicarbonate (HCO₃⁻) ku-plasma.

Ukubaluleka Okubalulekile Kokuhlolwa Kwe-Hemoglobin

Njengoba kunendima ebalulekile ye-hemoglobin, ukulinganisa ukuhlushwa kwayo nokuhlola ikhwalithi yayo kuyinsika eyisisekelo yezokwelapha zanamuhla. Ukuhlolwa kwe-hemoglobin, okuvame ukuba yingxenye ye-Complete Blood Count (CBC), kungenye yezindlela zokuhlola ezivame kakhulu zezokwelapha. Ukubaluleka kwayo akunakuphikiswa ngenxa yezizathu ezilandelayo:

Ukuqapha Ukuqhubeka Kwesifo Nokwelashwa:

Ezigulini ezitholakale zine-anemia, ukulinganisa i-hemoglobin ngokulandelana kubalulekile ukuqapha ukusebenza kahle kokwelashwa, njengokwengezwa kwensimbi, nokulandelela ukuqhubeka kwezifo ezingamahlalakhona eziyisisekelo njengokwehluleka kwezinso noma umdlavuza.

Ukutholwa kwe-Hemoglobinopathy:

Ukuhlolwa kwe-hemoglobin okukhethekile, njenge-hemoglobin electrophoresis, kusetshenziselwa ukuxilonga izifo zofuzo ezizuzwe njengefa ezithinta isakhiwo noma ukukhiqizwa kwe-hemoglobin. Izibonelo ezivame kakhulu yiSickle Cell Disease (ebangelwa uhlobo lwe-HbS olunephutha) kanye ne-Thalassemia. Ukutholwa kusenesikhathi kubalulekile ekuphathweni nasekululekweni ngofuzo.

Ukuhlolwa kwe-Polycythemia:

Izinga le-hemoglobin eliphezulu ngendlela engavamile lingabonisa i-polycythemia, isimo lapho umzimba ukhiqiza khona amangqamuzana egazi abomvu amaningi kakhulu. Lokhu kungaba ukuphazamiseka okuyinhloko komnkantsha wamathambo noma impendulo yesibili ku-hypoxia engapheli (isb., esifweni samaphaphu noma ezindaweni eziphakeme), futhi kuthwala ingozi ye-thrombosis.

Ukuhlolwa Nokuhlolwa Kwempilo Okuvamile: Ukuhlolwa kwe-hemoglobin kuyingxenye evamile yokunakekelwa kwangaphambi kokubeletha, ukuhlolwa kwangaphambi kokuhlinzwa, kanye nokuhlolwa kwempilo ejwayelekile. Kusebenza njengesibonakaliso esibanzi sempilo iyonke kanye nesimo sokudla okunempilo.

Ukuphathwa Kwesifo Sikashukela: Nakuba kungeyona i-hemoglobin ejwayelekile, ukuhlolwa kwe-Glycated Hemoglobin (HbA1c) kulinganisa ukuthi ingakanani i-glucose enamathele ku-hemoglobin. Kubonisa amazinga ajwayelekile kashukela egazini ezinyangeni ezi-2-3 ezedlule futhi kuyindinganiso yegolide yokulawula i-glycemic yesikhathi eside ezigulini ezinesifo sikashukela.

Isiphetho

I-hemoglobin ingaphezu kakhulu nje komthwali we-oxygen olula. Iwumshini wama-molecule oklanywe kahle kakhulu, osebenzisa ukubopha ngokubambisana kanye nokulawula i-allosteric ukuze kuthuthukiswe ukulethwa kwe-oxygen ngokuphendula izidingo zomzimba eziguquguqukayo. Ngenxa yalokho, ukulinganisa kwe-hemoglobin emtholampilo akuyona nje inombolo embikweni webhubhu; iyithuluzi elinamandla, elingangenisi ukutheleleka kanye nokuqapha. Inikeza isithombe esibalulekile sempilo yomuntu ye-hematological kanye neyonke, okwenza kube lula ukuxilonga izimo ezishintsha impilo, ukuqapha izifo ezingamahlalakhona, kanye nokulondolozwa kwempilo yomphakathi. Ukuqonda kokubili ubuhlakani bayo bezinto eziphilayo kanye nokubaluleka kwayo kwezokwelapha kugcizelela ukuthi kungani le phrotheni ethobekile ihlala iyitshe lesisekelo lesayensi ye-physiological kanye nezokwelapha.