I-photosynthesis inqubo lapho impilo, njengoba sazi, ingaba khona. Akuzuzisi izitshalo kuphela, kepha nezilwane njengoba siphefumula umoya-mpilo, igesi ekhishwa ngamaqabunga.
Kuyathakazelisa kakhulu ukwazi ngokujula kwe-photosynthesis, njengoba kunezigaba eziningana, futhi kukhona nezitshalo ezithile, ngenxa yezimo zezulu ezihlala kuzo, ezifunde ukukwenza ngendlela ehluke kancane.
Yini i-photosynthesis?
La i-photosynthesis inqubo lapho izitshalo ziguqula ukukhanya kwelanga kube ngamandlangakho-ke, bakwenza emini kuphela. Labo abaphethe ukufeza lo msebenzi obalulekile yibo ama-chloroplast, okuyizakhiwo eziluhlaza okotshani ezitholakala emaqabungeni.
Umbala wabo ubangelwa i-chlorophyll, eyi-biomolecule ngaphandle kwayo umbuso wezitshalo obungeke wenze i-photosynthesize. Kubaluleke kakhulu lokho izitshalo ezinamaqabunga ahlukahlukene (isb. okuluhlaza nokuphuzi ngokwesibonelo) zikhula kancane kunalawo anamaqabunga aluhlaza ngokuphelele. Ngaphezu kwalokho, basengozini enkulu yokukhanya kwelanga, ukuhlupheka kusha ngokushesha okukhulu kunalokho okuluhlaza.
Uhlelo lwe-photosynthesis yezitshalo lumi kanje:
Isithombe - Wikimedia / Meily Poot
Ziyini izigaba ze-photosynthesis ezitshalweni?
Njengoba besilindele ekuqaleni, i-photosynthesis inezigaba ezimbili, okuyilezi:
Isigaba sokukhanya
Isigaba sokukhanya yiso esenzeka emini. Singasho ukuthi yi-photosynthesis uqobo; hhayi ngeze, kunjalo emini lapho ilanga liphakeme futhi ngenxa yalokho lapho izitshalo zingathola amandla alo okukhanya
Kuqukethe ukuguqula lokho kukhanya kube ngamandla, ikakhulukazi ngesimo se-ATP (adenosine triphosphate) ne-NADPH (nicotinamide adenine dinucleotide phosphate), ngosizo lwamanzi nomoya-mpilo izimpande namaqabunga okumunca ngokulandelana.
Isigaba esimnyama
La isigaba esimnyama yisigaba sokugcina se-photosynthesis, futhi siqukethe ukuguqula isikhutha nezinye izinto zibe ushukela, okwakha ukudla kwezitshalo.
Ukwenza lokhu, basebenzisa i-ATP ne-NADPH ekhiqizwa esigabeni esincane, futhi benza nezinqubo ezimbili ezengeziwe: ukulungiswa kwekhabhoni kuma-carbohydrate, nomjikelezo kaCalvin. Kule nqubo yokugcina, izinto eziphilayo zigcinwa njenge-glucose.
Ngabe zonke izitshalo zithwebula izithombe ngendlela efanayo?
Akunjalo ngempela. Eqinisweni, kuye ngokuthi bayilungisa kanjani ikhabhoni, izinhlobo ezintathu zezitshalo zitholakele:
- Izitshalo ze-C3: yilabo abalungisa i-carbon dioxide emjikelezweni kaCalvin. Yibo bonke.
- Izitshalo ze-C4: abakwenzayo ukuguqula i-carbon dioxide ibe yi-malate, ezothathwa ihanjiswe kumaseli akhiqiza i-CO2 ne-pyruvate. Kungaleso sikhathi kuphela lapho umjikelezo kaCalvin uzoqala. Ulwazi oluningi.
- Izitshalo ze-CAM: yizitshalo, ngenxa yamazinga okushisa aphezulu emini, ezigcina izimbotshana zazo zivaliwe kuze kube sebusuku. Ngenxa yalokho, abakwazi ukumunca isikhutha ngakho-ke i-photosynthesize. Ngakho-ke, bayamunca ebusuku kuguqulwe kube yi-malate, okuthi emini ibavumele ukuthi bakhiqize i-CO2 futhi benze umjikelezo kaCalvin. Ulwazi oluningi.
Uyini umsebenzi we-photosynthesis?
Ngokuyinhloko ku- uguqule amandla elanga abe ngukudla kwezitshalo ngochungechunge lokuphendula kwamakhemikhali lapho bengasebenzisi khona ukukhanya kwelanga kuphela, kepha futhi ne-carbon dioxide namanzi. Ngenxa yalokho, bakhipha umoya-mpilo, igesi sonke esincike ekuphefumuleni.
Manje, kubalulekile ukucacisa ukuthi ukuxoshwa kwe-O2 akubalwa njengomsebenzi, kepha njengomphumela we-photosynthesis. Izilwane, kufaka phakathi abantu, zincike embusweni wezitshalo ukuze zibe khona. Kepha, kungakumangaza ukwazi ukuthi, yize izitshalo zasemhlabeni zibaluleke kakhulu empilweni, uma kufanele sisho ukuthi yisiphi isidalwa esiphilayo esikhiqiza umoya-mpilo omningi, singamangala.
I-Phytoplankton, umkhiqizi we-oxygen engafika kuma-85%
Yebo, i-phytoplankton, izinto eziphilayo ezihlala ezindaweni zasemanzini (izilwandle, amaxhaphozi, imifula), okuthi, ngokumunca amandla elanga, kwenziwe i-photosynthesis, kukhishwe umoya-mpilo. Eziningi zezinto eziyenzayo yi-cyanobacteria, ulwelwe oluhlaza kanye izisu.
Ngakho-ke, bona hhayi amahlathi ayisisekelo sempilo. Kepha hhayi kuphela ngenxa yomoya-mpilo, kepha futhi ngoba amaketanga okudla aqala ngawo. Noma yiluphi ushintsho olwenzeka emanzini, njengokushisa, noma i-acidification yawo, kuzobavimbela ekwenzeni imisebenzi yabo ngokujwayelekile.
I-Phytoplankton ikhiqiza ngaphezu kwesigamu somoya-mpilo otholakala kule planethiKungakho kubaluleke kakhulu ukunakekelwa kwezilwandle, kepha nemvelo yomhlaba, ngoba asikwazi ukukhohlwa ukuthi ukugawulwa kwamahlathi nokungcola yizimbangela ezimbili zokuthi ushintsho lwesimo sezulu luyashesha.
Siyethemba ukuthi konke okufundile nge-photosynthesis kube wusizo kuwe.