Ukubaluleka kwe-Folate ekukhiqizweni kwe-DNA
I-Folate (i-vitamin B9) iyisakhi esivame ukukhulunywa ngaso kumongo wempilo yokukhulelwa. Kodwa-ke, indima yayo idlulela ngalé kwalokho: i-folate "iyisihluthulelo" samakhemikhali ekukhiqizweni nasekulungisweni kwe-DNA kuwo wonke amaseli omzimba. Ngaphandle kwe-folate eyanele, umzimba uyazabalaza ukwakha i-DNA entsha ngempumelelo, ukulungisa umonakalo wezakhi zofuzo, nokwenza ukuhlukaniswa kwamaseli okuvamile. Lesi sihloko sixoxa ngokuthi kungani i-folate ibaluleke kangaka ekukhiqizweni kwe-DNA, ukuthi isebenza kanjani, umthelela wokuntuleka, kanye nemithombo kanye nendlela yokuhlangabezana nezidingo zayo.
Kuyini i-folate?
I-Folate uhlobo lwemvelo lwe-vitamin B9 olutholakala ekudleni, ikakhulukazi imifino eluhlaza, amantongomane, nezithelo ezithile. Okwamanje, i-"folic acid" uhlobo lokwenziwa oluvame ukusetshenziswa ezithasiseleni nasekuqiniseni ukudla. Zombili ekugcineni zisebenza ngendlela efanayo ye-metabolic emzimbeni—yize kukhona umehluko endleleni ezisebenza ngayo futhi zisetshenziswa ngayo.
Emzimbeni, i-folate ayisebenzi yodwa. Isebenza njenge-coenzyme, umngane wama-molecule osiza ama-enzyme ukuthi enze ukusabela kwamakhemikhali. Enye yezindima zayo ezibaluleke kakhulu ukuthutha amayunithi e-carbon eyodwa adingekayo ukwakha i-DNA.
Indima ye-DNA nokuthi kungani ukukhiqizwa kwayo kubalulekile
I-DNA (i-deoxyribonucleic acid) "iyincwadi yemiyalelo" egcina ulwazi lwezakhi zofuzo. Iseli ngalinye lidinga i-DNA ukuze liqondise ukwakheka kwamaprotheni, lilawule ukukhula, futhi ligcine ukusebenza okuvamile kwezicubu. Ukukhiqizwa kwe-DNA kwenzeka njalo lapho iseli lihlukana—isibonelo, ngesikhathi sokukhula, ukuphulukiswa kwamanxeba, ukwakheka kwamangqamuzana abomvu egazi, kanye nokukhula kombungu.
Ngakho-ke, izicubu ezihlukana ngokushesha kakhulu zizwela kakhulu ekusweleni kwe-folate. Izibonelo zifaka phakathi umongo wamathambo (okhiqiza amangqamuzana egazi), izicubu zomgudu wokugaya ukudla, kanye nezicubu zombungu ekuqaleni kokukhulelwa. Lapho ukukhiqizwa kwe-DNA kuphazamiseka, imiphumela ingafaka phakathi ukuhlukana kwamaseli okuphazamiseka, ukulimala kwama-chromosome, kanye nokukhubazeka kokukhula.
Indlela i-folate edlala ngayo indima ekukhiqizweni kwe-DNA
Indima ye-folate ekukhiqizweni kwe-DNA yenzeka ngokuyinhloko ngendlela "yokusetshenziswa kwe-carbon eyodwa". Kalula nje, i-folate isiza ekuhlinzekeni ngamakhemikhali adingekayo ukwakha izisekelo ze-nitrogen - izakhi eziyinhloko ze-DNA.
Izinqubo ezimbili ezincike kakhulu ku-folate yilezi:
1. Ukwenziwa kwe-Nucleotide (izinto zokusetshenziswa ze-DNA)
I-DNA yakhiwe ngama-nucleotide. I-nucleotide eyodwa ebalulekile yi-thymidine, etholakala ekusabeleni okwakha i-dTMP (deoxythymidine monophosphate). Lokhu kusabela kudinga i-folate derivative, i-5,10-methylene-THF, njengomnikeli weyunithi yekhabhoni. Ngaphandle kwe-folate, ukwakheka kwe-thymidine kuyaphazamiseka, okushiya amaseli engenazo "izinhlamvu" ezidingekayo ukwakha i-DNA.
2. I-DNA methylation (ukulawulwa kokubonakaliswa kwezakhi zofuzo)
I-Folate nayo ihilelekile ekwakhiweni kwe-S-adenosylmethionine (SAM), umnikeli oyinhloko we-methyl emzimbeni. I-DNA methylation inqubo yokunamathisela amaqembu e-methyl ku-DNA, edlala indima ekuvuleni noma ekuvaleni izakhi zofuzo ezithile. Nakuba i-methylation ingahilelekile ngqo ekukhiqizweni kwe-DNA, le nqubo ibalulekile ekuzinzeni kwezakhi zofuzo, ukulawulwa kokukhula kwamaseli, kanye nokuthuthukiswa kombungu.
Ngamanye amazwi, i-folate inegalelo ezicini ezimbili: ukuhlinzeka ngezinto zokwakha i-DNA nokusiza ekulawuleni indlela i-DNA esetshenziswa ngayo amaseli.
Umthelela wokuntuleka kwe-folate ku-DNA nasemaseli
Uma i-folate inganele, umzimba uhlangabezana nokuphazamiseka ekwakhekeni kwe-DNA, ikakhulukazi ekuhlukaniseni amaseli ngokushesha. Imiphumela eyinhloko ihlanganisa:
- Izinkinga zokuhlukana kwamaseli nokukhula kwamaseli
Ukuntuleka kwe-folate kungabangela i-megaloblastic anemia, isimo lapho amangqamuzana abomvu egazi eba makhulu kunokujwayelekile futhi angavuthwa kahle ngenxa yokungasebenzi kahle kokwakheka kwe-DNA. Izimpawu zingafaka ubuthakathaka, ukukhathala, ukuphaphatheka, ukuphefumula okunzima, kanye nobunzima bokugxilisa ingqondo.
- Ukwanda komonakalo we-DNA
Ukuntuleka kwe-thymidine kungabangela "amaphutha okubhangqa" ku-DNA, njengokufaka i-uracil esikhundleni se-thymine. Lokhu kungabangela ukuphuka kweketanga le-DNA ngesikhathi senqubo yokulungisa ephindaphindwayo.
– Ingozi yezinkinga ngesikhathi sokukhulelwa
Ekuqaleni kokukhulelwa, umbungu ukhula ngokushesha. Ukuntuleka kwe-folate kungandisa ingozi yokukhubazeka kwe-neural tube (njenge-spina bifida) ngoba ukuhlukaniswa kwamaseli kanye nokwakheka kwezicubu ze-neural kuncike kakhulu ekukhiqizweni kwe-DNA okubushelelezi.
- Izinkinga zokugaya ukudla kanye nesimiso somzimba sokuzivikela
Amaseli e-mucosal emathunjini kanye namaseli omzimba avame ukwanda. Ukuntuleka kwe-folate kungaphazamisa ukuvuselelwa kolwelwesi lokugaya ukudla futhi kunciphise amasosha omzimba.
I-Folate, i-homocysteine, kanye nekhwalithi ye-genome
I-Folate nayo ihilelekile ekusetshenzisweni kwe-homocysteine, okuyingxenye ephakathi ekusetshenzisweni kwe-amino acid methionine. I-Folate isiza ukuguqula i-homocysteine ibuyele ku-methionine. Uma i-folate iphansi, amazinga e-homocysteine anganda. Amazinga aphezulu e-homocysteine avame ukuhlotshaniswa nezinkinga zenhliziyo futhi angabonisa ukuphazamiseka kwe-metabolism ye-one-carbon, okuhlobene nokuzinza kwe-DNA kanye ne-methylation.
Lokhu kusebenzisana kusikisela ukuthi i-folate ayibalulekile nje kuphela “ekunyatheliseni” i-DNA entsha, kodwa futhi nasekugcineni izimo zamakhemikhali ezisekela ikhwalithi ye-genome iyonke.
Imithombo ye-folate ekudleni
Ngenxa yokuthi i-folate iyancibilika emanzini futhi ayizweli ekushiseni, izindlela zokupheka zingathinta inani le-folate esele. Ukupheka ngokweqile kunganciphisa amazinga e-folate. Imithombo emihle ye-folate ihlanganisa:
– Imifino eluhlaza: isipinashi, i-kale, i-broccoli, i-asparagus
- Imifino: ubhontshisi wezinso, ubhontshisi we-lentile, ubhontshisi we-chickpeas
– Izithelo: ukwatapheya, i-orenji
– Isibindi kanye nemikhiqizo ethile yezilwane
– Imikhiqizo eqinisiwe (kuye ngokuthi inqubomgomo yezwe): ufulawa, okusanhlamvu, noma isinkwa esinothe nge-folic acid
Ukudla ukudla okuhlukahlukene kuyindlela engcono kakhulu yokuqinisekisa ukuthi i-folate eyanele kanye namanye amavithamini e-B asebenza ndawonye (njenge-B12 kanye ne-B6).
Izithasiselo: zidingeka nini?
Izithako ze-folic acid zivame ukunconywa emaqenjini athile, ikakhulukazi:
– Abesifazane abahlela ukukhulelwa kanye ne-trimester yokuqala
Ngenxa yokuthi ukwakheka kwamapayipi ezinzwa kwenzeka kusenesikhathi kakhulu—ngaphambi kokuba abantu abaningi baqaphele nokuthi bakhulelwe—kumelwe kutholakale ukuthi kudliwe i-folate eyanele ngaphambi kokukhulelwa.
– Abantu abanezinkinga zokungenisa ukudla okuncane noma zokumuncwa okungasebenzi kahle
Isibonelo, izinkinga ezithile zomgudu wokugaya ukudla noma izindlela zokudla ezilinganiselwe kakhulu.
Kodwa-ke, ukusetshenziswa kwezithasiselo kufanele kuqondiswe yizincomo zochwepheshe bezempilo, ikakhulukazi njengoba i-folate ingafihla izimpawu ze-anemia ebangelwa ukuntuleka kwe-vitamin B12. Lokhu kusho ukuthi umuntu angase abonakale ethuthuka ekubalweni kwegazi lakhe, kodwa ukulimala kwemizwa ngenxa yokuntuleka kwe-B12 kuzoqhubeka uma kungalashwa.
Amathiphu awusizo okuhlangabezana nezidingo ze-folate
Izinyathelo ezilula ezingasiza:
1. Yidla imifino eluhlaza nsuku zonke, khetha uhlobo oluthile (isibonelo, ukushintshanisa isipinashi ne-broccoli).
2. Faka amantongomane noma imikhiqizo yawo ecutshunguliwe izikhathi eziningana ngesonto.
3. Khetha izindlela zokupheka ezimfushane njengokupheka ngomusi noma ukuthosa ngokushesha ukuze ugcine i-folate.
4. Uma uhlela ukukhulelwa, xhumana nezithasiselo ze-folate kusenesikhathi.
5. Qiniseka ukuthi ukudla kwakho i-vitamin B12 kwanele, ikakhulukazi kubantu abadla imifino/abangadli inyama.
I-Penutup
I-Folate iyisakhi esibalulekile esiyisisekelo ekukhiqizweni kwe-DNA. Isiza ekwakheni ama-nucleotide—izakhi ze-DNA—futhi isekela i-methylation ye-DNA, ebalulekile ekulawulweni kwezakhi zofuzo kanye nokuqina kwezakhi zofuzo. Ukuntuleka kwe-folate kungaphazamisa ukuhlukana kwamaseli, kwandise umonakalo we-DNA, kubangele i-megaloblastic anemia, futhi kwandise ingozi yokuphazamiseka kokukhula kwengane esanda kuzalwa. Ngakho-ke, ukuqinisekisa ukudla okwanele kwe-folate ngokudla okunomsoco, futhi uma kudingeka, izithasiselo ezifanele, kuwukutshalwa kwezimali okubalulekile empilweni yamaseli, ukukhula, kanye nokuvuselelwa kukho konke ukuphila.
Uma ufisa, ngingahlela lesi sihloko ukuze sihambisane nezilaleli ezithile eziqondiwe (isib., abafundi besikole samabanga aphezulu, abafundi bezempilo, noma umphakathi jikelele) noma ngengeze izinkomba zesayensi kanye nezibalo zezidingo zansuku zonke ngokweziqondiso zokudla okunempilo.
