Mehlala ea Lipotso le Puisano ea Likarabelo tse Lefifi
Likarabelo tse lefifi, tse tsejoang hape e le potoloho ea Calvin, ke mekhahlelo ea photosynthesis e hlahang kamora likarabelo tsa leseli. Likarabelong tsena, carbon dioxide e fetoloa tsoekere ho sebelisoa ATP le NADPH tse hlahisoang likarabelong tsa leseli. Ho utloisisa likarabelo tse lefifi ho bohlokoa bakeng sa baithuti ba baeloji, haholo-holo ba ithutang photosynthesis. Sehloohong sena, re tla akaretsa mathata a mang a mohlala le ho buisana ka likarabelo tse lefifi.
Pendahuluan
Potoloho ea Calvin e etsahala ka har'a stroma ea chloroplast 'me e kenyelletsa mehato e' maloa ea bohlokoa. Ts'ebetso ena e reheletsoe ka potoloho ea Calvin ka mor'a rasaense Melvin Calvin, ea hlalositseng mokhoa ona. Mehato e meholo potolohong ea Calvin e kenyelletsa ho lokisa khabone, ho fokotsa le ho nchafatsa ribulose bisphosphate (RuBP). Mona ke kakaretso e khutšoanyane ea mohato ka mong:
1. Ho Tiisa Khabone: Sethaleng seo khabone e tshwarwang ke RuBP ka thuso ya enzyme ya rubisco, e hlahisang metsoako e mahareng.
2. Phokotso: Metswako e bopilweng ka ho tiya ha khabone e fokotswa ho ba glyceraldehyde-3-phosphate (G3P). Ts'ebetso ena e sebedisa ATP le NADPH.
3. Tsosoloso ea RuBP: Limolek'hule tse ling tsa G3P li sebelisetsoa ho hlahisa tsoekere, ha tse ling li sebelisetsoa ho hlahisa RuBP hape.
Lipotso tsa Mehlala le Puisano
Ho utloisisa potoloho ea Calvin hamolemo, ha re shebeng mehlala e meng ea lipotso tse atisang ho hlaha litlhahlobong hammoho le lipuisano tsa tsona.
Mohlala oa Potso ea 1
Potso:
Karolo ea ATP le NADPH ke efe liketsong tse lefifi tsa photosynthesis, hona li hlahisoa joang liketsong tsa leseli?
Puisano:
Likarabelong tse lefifi, ATP le NADPH li sebetsa e le mehloli ea matla le metsoako e fokotsang e sebelisoang ho fetola carbon dioxide hore e be glucose. ATP e fana ka matla a mahala bakeng sa karabelo ea lik'hemik'hale, ha NADPH e fana ka lielektrone tse hlokahalang bakeng sa phokotso.
Limolek'hule tsena tse peli li hlahisoa nakong ea karabelo ea khanya ea photosynthesis, e hlahang ho thylakoid ea li-chloroplast. Likarabelong tsa khanya, khanya e monngoa ke chlorophyll, e leng se bakang karohano ea metsi hore e be oksijene, liprothone le lielektrone. Lielektrone tse lokolotsoeng li tsamaea ka har'a ketane ea lipalangoang tsa lielektrone, li fokotsa NADP+ ho ea ho NADPH le ho kopanya ATP ka photophosphorylation.
Mohlala oa Potso ea 2
Potso:
Hlalosa mekhahlelo ea ho tiea ha khabone potolohong ea Calvin le lienzyme tse ka sehloohong tse amehang ts'ebetsong ena.
Puisano:
Ho tiea ha khabone ke mohato oa pele oa potoloho ea Calvin, moo khabone e ntšitsoeng sepakapakeng 'me e kopanngoa le RuBP (ribulose-1,5-bisphosphate) ho etsa motsoako o sa tsitsang oa khabone tse tšeletseng. Motsoako ona o aroloa hang-hang hore e be limolek'hule tse peli tsa 3-phosphoglycerate (3-PGA).
Enzyme e amehang haholo ts'ebetsong ena ke ribulose-1,5-bisphosphate carboxylase/oxygenase, eo hangata e bitsoang rubisco. Rubisco ke e 'ngoe ea lienzyme tse ngata ka ho fetisisa Lefatšeng, ka lebaka la karolo ea eona ea bohlokoa lits'ebetsong tsa taolo ea khabone lefatšeng.
Mohlala oa Potso ea 3
Potso:
Ho hlokahala limolek'hule tse kae tsa ATP le NADPH ho hlahisa molek'hule e le 'ngoe ea tsoekere ho pholletsa le potoloho ea Calvin?
Puisano:
Ho hlahisa molek'hule e le 'ngoe ea glucose (C6H12O6), potoloho ea Calvin e tlameha ho etsahala ka makhetlo a tšeletseng hobane potoloho ka 'ngoe e kenya athomo e le 'ngoe feela e ncha ea carbon masapong a carbon a tlhaho. Potolohong ka 'ngoe ea Calvin, ho lokisoa le ho fokotsoa ha molek'hule e le 'ngoe ea 3-PGA ho molek'hule e le 'ngoe ea glyceraldehyde-3-phosphate (G3P) ho hloka 3 ATP le 2 NADPH.
Kahoo, ho hlahisa molek'hule e le 'ngoe ea tsoekere, ho hlokahala limolek'hule tse 18 tsa ATP le limolek'hule tse 12 tsa NADPH (ATP tse 3 le NADPH tse 2 ka potoloho ka makhetlo a 6).
Mohlala oa Potso ea 4
Potso:
Ho etsahala'ng ka limolek'hule tsa G3P tse hlahisoang potolohong ea Calvin, 'me G3P e bapala karolo joang tlhahisong ea tsoekere?
Puisano:
Mothating oa Calvin, limolek'hule tse ling tsa G3P tse hlahisoang li sebelisetsoa ho nchafatsa RuBP, e leng se lumellang potoloho ho tsoela pele. Leha ho le joalo, G3P e 'ngoe e sebelisoa e le selelekela sa tlhahiso ea glucose le lik'habohaedreite tse ling.
Ka tlwaelo, bakeng sa dimolekhule tse tsheletseng tsa G3P tse hlahiswang, tse hlano di sebediswa ho hlahisa dimolekhule tse tharo tsa RuBP, ha molekhule o le mong wa G3P o tswa potolohong ho kenya letsoho tlhahisong ya glucose le dimolekhule tse ding tse kang starch le cellulose. Ka tsela ya biosynthetic ka hara stroma, dimolekhule tse pedi tsa G3P di kopanngwa ho etsa molekhule o le mong wa glucose kapa fructose.
Mohlala oa Potso ea 5
Potso:
Ke hobane'ng ha liketso tse lefifi hangata li nkoa e le potoloho, hona bohlokoa ba tsona ke bofe ts'ebetsong ea photosynthesis?
Puisano:
Likarabelo tse lefifi li bitsoa potoloho ea Calvin hobane qetellong ea letoto la likarabelo, RuBP e sebelisitsoeng ho kenngoeng ha khabone ea pele e tsosolosoa e le hore e ka sebelisoa hape potolohong e latelang. Bokhoni ba ho nchafatsa RuBP bo bohlokoa hobane bo lumella limela ho etsa liketso tsa ho kenngoeng ha khabone khafetsa, li sebetsana le carbon dioxide e ngata hore e be lintho tse phelang.
Bohlokoa ba potoloho ea Calvin ho photosynthesis ke hore e nolofalletsa ho tšoaroa ha carbon dioxide ka katleho, e e fetola mofuta oa matla a lik'hemik'hale a ka sebelisoang ke limela le lintho tse ling tse phelang e le mafura le joaloka selelekela sa ho kopanngoa ha limolek'hule tse ling tsa lintho tse phelang. Ho tsoela pele ha potoloho ena ke senotlolo sa ho tšehetsa tikoloho ea lefats'e hobane e fana ka tsoekere, e leng ea bohlokoa bakeng sa bophelo.
Qetello
Likarabelo tse lefifi tsa photosynthesis ke karolo ea bohlokoa ho utloisiseng kamoo limela li fetolang matla a letsatsi hore e be matla a lik'hemik'hale a thusang le ho boloka matla ana bakeng sa tšebeliso lits'ebetsong tse fapaneng tsa baeloji. Ka ho utloisisa lits'ebetso tsa ho lokisa khabone, ho fokotsa le ho nchafatsa RuBP potolohong ea Calvin, re ka ananela bohlokoa ba photosynthesis tikolohong ea rona ea tikoloho le kamoo e tšehetsang bophelo Lefatšeng. Re tšepa hore lipotso tsena tsa mehlala le litharollo li tla thusa babali ho itokisetsa tlhahlobo le ho tebisa kutloisiso ea bona ea ts'ebetso ena e ikhethang.
