Ukubaluleka kwe-Hemoglobin ekuThuthweni kwe-Oxygen
I-hemoglobin ingenye yamaprotheni abaluleke kakhulu emzimbeni womuntu, esebenza njengomthwali oyinhloko womoya-mpilo ovela emaphashini uye kuzo zonke izicubu zomzimba. Le molekyuli itholakala kumaseli abomvu egazi (ama-erythrocyte) futhi inesakhiwo esiyinkimbinkimbi esivumela ukuthi ibophe futhi ikhulule umoya-mpilo ngempumelelo. Kulesi sihloko, sizohlola ukubaluleka kwe-hemoglobin, ukuthi le phrotheni isebenza kanjani ekuthuthweni komoya-mpilo, nokuthi kwenzekani lapho lolu hlelo lungasebenzi kahle.
Kuyini i-Hemoglobin?
I-Hemoglobin iyiprotheni ye-tetrameric eyakhiwe ngama-subunit amane e-polypeptide: ama-subunit amabili e-alpha kanye nama-subunit amabili e-beta. I-subunit ngayinye iqukethe i-molecule ye-heme equkethe i-athomu yensimbi enkabeni yayo. Le athomu yensimbi ibalulekile ekusebenzisaneni ngqo nomoya-mpilo. I-hemoglobin ecebile nge-oxygen ibizwa ngokuthi i-oxyhemoglobin, kanti i-hemoglobin engaboshiwe ibizwa ngokuthi i-deoxyhemoglobin.
Umsebenzi we-Hemoglobin Ekuthuthweni Kwe-Oxygen
Ngesikhathi sokuphefumula, umoya-mpilo ophefumulwayo ungena e-alveoli emaphashini. Ukusuka lapho, umoya-mpilo uyasakazeka ngama-capillary e-pulmonary uye emangqamuzaneni abomvu egazi. Lapha, i-hemoglobin idlala indima yayo ngokubopha umoya-mpilo otholakalayo. I-hemoglobin inezindawo ezine zokubopha umoya-mpilo, futhi i-molecule ngayinye eboshiwe yomoya-mpilo ikhulisa ukusondelana kwe-hemoglobin kwi-molecule elandelayo yomoya-mpilo. Le nqubo yaziwa ngokuthi 'ukubambisana' futhi iyisici esisebenza kahle kakhulu sale molekyuli.
Uma umoya-mpilo usuboshiwe, igazi liphonswa yinhliziyo ngokusebenzisa uhlelo lokujikeleza kwegazi, lijikeleza kuwo wonke umzimba. Lapho igazi elinomoya-mpilo lifika ezicutshini ezidingayo, i-hemoglobin ikhipha umoya-mpilo, ngaleyo ndlela inikeze umoya-mpilo odingekayo ezinqubweni ezibalulekile ze-metabolic zamangqamuzana njengokukhiqizwa kwe-ATP ngokusebenzisa i-oxidative phosphorylation. Ngakho-ke, i-hemoglobin idlala indima ebalulekile ekuhlinzekeni umzimba umoya-mpilo owudingayo ukuze ugcine imisebenzi evamile yomzimba.
Uhlelo Lokulawula I-Hemoglobin
I-hemoglobin ayisebenzi nje kuphela ukubopha umoya-mpilo kodwa futhi ihilelekile ekulawuleni ukungena nokukhululwa komoya-mpilo. Izici eziningana ezithinta ikhono le-hemoglobin lokubopha umoya-mpilo zifaka:
1. Ukucindezela Okungaphelele Komoya-mpilo (pO2): I-Hemoglobin inokusondelana okuphezulu komoya-mpilo lapho ingcindezi ephezulu yomoya-mpilo iphakama, njengasemaphashini. Ngokuphambene nalokho, lapho ingcindezi yomoya-mpilo iphansi, njengasezicutshini zomzimba, ukusondelana kwayo kuyancipha, okuvumela ukuthi umoya-mpilo ukhishwe.
2. I-pH (Umphumela we-Bohr): Uma amangqamuzana esebenzisa umoya-mpilo futhi ekhiqiza i-CO2, andisa ukugcwala kwama-ion e-hydrogen (H+), okwenza indawo ezungezile ibe ne-asidi eningi. I-Hemoglobin isabela ngokukhipha umoya-mpilo owengeziwe, owaziwa ngokuthi umphumela we-Bohr.
3. Ukuhlushwa kwe-CO2: Ukuhlushwa kwe-CO2 egazini kunciphisa nokusondelana kwe-hemoglobin nomoya-mpilo, okwenza kube lula ukukhishwa komoya-mpilo ezicutshini eziwudingayo.
4. 2,3-Bisphosphoglycerate (2,3-BPG): Le molekyuli ibopha i-hemoglobin futhi inciphise ukusondelana kwayo nomoya-mpilo, isize ekukhishweni komoya-mpilo ezicutshini zomzimba.
I-Pathology kanye Nezimo Ezingajwayelekile Ezihlobene ne-Hemoglobin
Uma i-hemoglobin ingasebenzi kahle, izimo ezahlukene zezokwelapha zingavela. Esinye sezifo ezivame kakhulu i-anemia, isimo esibonakala ngokuntuleka kwe-hemoglobin noma inani eliphansi lamaseli abomvu egazi emzimbeni. Lokhu kuholela ekunciphiseni kwamandla okuthwala umoya-mpilo, okungaholela ekukhathaleni, ebuthakathakeni, nakwezinye izimpawu. I-anemia ingabangelwa izici ezahlukahlukene, njengokuntuleka kwensimbi, ukulahlekelwa yigazi, noma izinkinga ngokukhiqizwa kwamaseli abomvu egazi.
Ngaphandle kwe-anemia, kunezimo eziningana zezakhi zofuzo ezithinta isakhiwo kanye nomsebenzi we-hemoglobin. Izibonelo zifaka:
1. I-Sickle Cell Anemia: Ukuguquka kwezakhi zofuzo kushintsha isimo se-hemoglobin, okwenza amangqamuzana abomvu egazi abe sesimweni sesikele futhi angaguquguquki kakhulu, okungavimba ukugeleza kwegazi futhi kubangele ubuhlungu kanye nomonakalo wezitho zomzimba.
2. I-Thalassemia: Isifo sofuzo esinciphisa ukukhiqizwa kohlobo olulodwa lwe-globin chain ku-hemoglobin, okubangela ukungalingani esakhiweni sama-molecule kanye nokuwohloka okusheshayo kwamaseli abomvu egazi.
3. I-Methemoglobinemia: Isimo lapho i-hemoglobin eningi kakhulu ishintsha ibe uhlobo olungakwazi ukubopha umoya-mpilo, olubangelwa ukushintsha kwezakhi zofuzo noma ukuchayeka kumakhemikhali athile.
Indima Ye-Hemoglobin Ekuxilongweni Nasekwelashweni Kwezokwelapha
Ukulinganisa amazinga e-hemoglobin kuyingxenye ebalulekile yokuxilongwa kwezokwelapha kanye nokuhlolwa okuvamile. Amazinga e-hemoglobin ajwayelekile ayahlukahluka kuye ngobudala bomuntu kanye nobulili bakhe, kodwa ngokuvamile asukela ku-13.8–17.2 amagremu nge-deciliter (g/dL) kwabesilisa kanye no-12.1–15.1 g/dL kwabesifazane. Ukwehla noma ukwanda kwamazinga e-hemoglobin kungabonisa izimo ezahlukene zempilo ezidinga ukunakekelwa kwezokwelapha.
I-hemoglobin nayo iyisisulu sokwelashwa kwezimo ezahlukahlukene. Isibonelo, iziguli ezine-anemia yokuntuleka kwensimbi zivame ukunikezwa izithasiselo zensimbi ukuze kwandiswe ukukhiqizwa kwe-hemoglobin. Ezimweni zofuzo ezifana ne-sickle cell anemia kanye ne-thalassemia, izindlela zokwelapha ezithuthukisiwe njengokwelashwa kwezakhi zofuzo kanye nokufakelwa komnkantsha wethambo seziqalile ukubonisa imiphumela ethembisayo.
Isiphetho
I-hemoglobin iyisici esibalulekile ohlelweni lokuthutha umoya-mpilo lomzimba womuntu, idlala indima ebalulekile ekuqinisekiseni ukuthi zonke izicubu zomzimba zithola umoya-mpilo eziwudingayo ukuze zisebenze kahle. Ukuqonda ukuthi i-hemoglobin isebenza kanjani nokuthi izici ezahlukene zithonya kanjani ukusebenza kwayo kusinika ukuqonda okubalulekile kokuthi imizimba yethu igcina kanjani i-homeostasis. Ngaphezu kwalokho, lolu lwazi lusinikeza nesiteji sokubona, ukuxilonga, nokwelapha izimo ezahlukahlukene ezithinta ukuthuthwa komoya-mpilo, ekugcineni kusize ekuthuthukiseni ikhwalithi yokuphila kwabantu abathintekile.
Ngocwaningo oluqhubekayo kule ndawo, kunethemba lokuthi singathuthukisa amathuluzi okuxilonga nawokwelapha asebenza kahle kakhulu ukuze sibhekane nezinkinga ezahlukahlukene ezihlobene ne-hemoglobin, siqinisekise ukuthi wonke umuntu angajabulela impilo enhle.
