Ifotosinthesisi yinkqubo enokuthi yenziwe zizityalo kuphela, kwaye apho zonke izilwanyana zixhomekeke ekubeni zikwazi ukuphefumla kwaye, ngenxa yoko, zikhona. Nangona thina bantu sihlala sicinga ukuba izityalo ezisemhlabeni zezona zijongene nobomi, into engothusiyo kwaphela kuba thina singabantu basemhlabeni nabangekho emanzini, eneneni ngabo bahlala ezilwandle, emilanjeni nasemigxobhozweni evelisa indawo ephezulu Ipesenti yale gesi ibalulekileyo.
Kodwa lumka, oko akuthethi kangako ukuba imithi, amasundu, kunye nezinye azibalulekanga ... kuba zibalulekile. Yonke into ibalulekile. Kwaye okukhona kukho izityalo kwiplanethi, kokubini emanzini nakumhlaba womhlaba, kokukhona iyantlukwano yobomi. Kodwa basinda njani? Ewe, ukuguqula ikhabhon diokside efumaneka emoyeni iye ekutyeni, ngexesha loko kwaziwa njenge isigaba esimnyama sefotosinthesisi.
Kwenziwa njani isigaba esimnyama sefotosinthesisi?
Umfanekiso - Wikimedia / Cheveri
Nangona igama layo linokulahlekisa, sisenzo esenzeka imini nobusuku kwizakhiwo ezibizwa ngokuba zii-chloroplast. Kwesi sigaba ikakhulu athathwe (adenosine triphosphate), ebalulekileyo kumandla kunye neNADPH (Inicotinamide adenine dinucleotide phosphate) eyi coenzyme enkosi apho ikharbon diokside ibophelela kuyo. Ngazo, iinkqubo ezininzi zeekhemikhali zenziwa kubo, zahlulwe zangamacandelo amabini:
Ukulungiswa kwekhabhoni
Nangona kungaxhomekeki kwinto yokuba kukho ukukhanya kwelanga ngelo xesha, kubalulekile ukuba uqaphele ukuba ngaphandle kwayo ngekhe kunikezwe, kuba ii-enzymes ezithile ezibandakanyekileyo zixhomekeke ekukhanyeni. Xa kuziwa ekulungiseni ikhabhon, izityalo zinokukwenza ngeendlela ezahlukeneyo. Inyaniso, Iingcali zeBotanists zichonge ukulungiswa kwe-CO2 ezintathu:
- C3 izityalo: zezona zixhaphakileyo. Bayayilungisa ngexesha lomjikelo kaCalvin (esiza kubona ngoku), ngaphandle kokulungiswa kwangaphambili.
- C4 izityalo: Ezi zezo apho ikharbhon diokside, emva kokuphendula nge-fossoenolpyruvate, ivelisa i-oxaloacetate, ethi kamva ibe lilishwa (iimolekyuli ezi-4 zekhabhoni). Le malate yinto eza kusiwa kwiiseli, kwaye apho ikharbon diokside iyimfuneko kumjikelo kaCalvin kunye nepyruvate.
- Izityalo zeCAM: ivela kwizityalo ezinamanzi. Ukuhlala kwimimandla apho amaqondo obushushu aphezulu ephezulu kakhulu, nalapho kukho imvula encinci, i-stomata ihlala ivaliwe emini ukunciphisa ilahleko yamanzi. Ebusuku bayavula, kwaye kulapho bafunxa khona i-CO2. Kodwa, njengakwizityalo zeC4, oku kuqala kunika imalate emva kothotho lweempendulo zamachiza, ezigcina zibonelela nge-CO2 emini. Iinkcukacha ezithe xaxe apha.
Umjikelo kaCalvin
Umjikelo kaCalvin yinkqubo apho icarbon dioxide iguqulwa yenziwa yiglucose, ezakusetyenziswa sisityalo ukuphefumla kwaye, njengomthombo wekhabhoni. Eli linqanaba lesibini le-photosynthesis, kwaye eyona ibaluleke kakhulu kwizilwanyana ezininzi, kuba enkosi kuyo izityalo zinokubakho, ke ngoko, zikhuphe ioksijini imini yonke nobusuku bonke.
Yenzeka phi inqanaba elimnyama lefotosinthesis?
Isigaba esimnyama yenzeka kwii-chloroplast. Ezi zizakhiwo zeselula ezifumaneka kwizinto eziphilayo ze-eukaryotic, kwaye zine-oval okanye i-spherical shape. Umsebenzi wawo ophambili kukuguqula amandla elangeni aye kumandla ekhemikhali, into eyenzeka ngexesha ifotosinthesis kwaye, ukuba ichane ngakumbi, ngexesha lesigaba sayo esimnyama.
Yenziwe ngemvulophu eyenziwe ziimbumba ezimbini ezinemibala efana neklorophyll, kunye nezinye izinto eziyimfuneko ukuze ikwazi ukufeza umsebenzi wayo.
Yintoni na isakhiwo chloroplast?
- Inwebu yangaphandle: iyangena kwaye ineeproteni. Igcina yahlukile kwisytoplasm.
- Inwebu yangaphakathi: ine stroma, ingingqi yayo enamanzi.
- Inwebu yethylakoid: kuyo kukho ii-thylakoids, ezifana neengxowa ezithe tyaba. Xa ezi zifakwe, zifefa.
Uyintoni umsebenzi wayo?
I-photosynthesis yenzeka ngaphakathi kwii-chloroplast, zombini isigaba sayo sokukhanya (ukuvelisa i-ATP kunye ne-NADPH kwi-membrane ye-tylokoid), kunye nenqanaba elimnyama (ukulungiswa kwekhabhon diokside kwi-stroma). Ayisiyiyo loo nto kuphela, kodwa Baphinde benze i-amino acid kwaye benze ii-acid ezinamafutha, zibalulekile kwizityalo ukuze zifumane ukutya. Ngale kutya, oko kukuthi, ngezi carbohydrate, iswekile kunye nesitatshi, banethuba lokukhula, lokuchuma kunye nokuvelisa imbewu yabo.
Ke ngaphandle kwefotosinthesisi umhlaba wethu ubuya kwahluka kakhulu. Kungenxa yoko le nto kufanelekile, kwaye inomdla, ukufunda ngakumbi malunga neentyatyambo ezisingqongileyo, kuba ngaphandle kwazo ngokuqinisekileyo akukho namnye kuthi obeya kuba lapha namhlanje.
Siyathemba ukuba okufundileyo malunga nesigaba esimnyama sefotosinthesisi kuluncedo kuwe.