Ingabe ingaphakathi lengqamuzana lesitshalo lifana noketshezi noma okuqinile? Yize lokhu kungase kuzwakale njengombuzo oyinqaba, ucwaningo olwenziwa eNyuvesi yase-Amsterdam lukhombisa ukuthi kungaba noma yikuphi, kuye ngokuthi kungakanani ukukhanya okukhanyisa kukho. Ama-chloroplasts ngaphakathi kwamangqamuzana ezitshalo enza uhlobo olusebenzayo lwento eshintshashintshayo.
Umbuzo wokuthi izitshalo zizizwa kanjani futhi zisabele kanjani endaweni ezizungezile uye wahlaba umxhwele ososayensi nezazi zefilosofi kusukela ngaleso sikhathi ezikhathini zasendulo. Eminyakeni engaphezu kwezinkulungwane ezimbili edlule, uPlato wabhala kweyakhe ethi “Timaeus” ukuthi izitshalo “zinomphefumulo” ozwa “imizwa, injabulo, ubuhlungu, nesifiso” kuyilapho kungenakho “ukwahlulela nokuhlakanipha.”
Ukunyakaza, noma ukunganyakazi
Nakuba ososayensi banamuhla bezovumelana kakhulu nalokhu kuhlola okuvezwe ngokusankondlo, ngeke bavumelane nenkulumo kaPlato yokulandelanisa yokuthi izitshalo “azinawo amandla okuzinyakazisa”; ukuba nezimpande akusho ukuthi izitshalo azikwazi ukunyakaza. Cabanga ngobhekilanga abancane abalandela ilanga nsuku zonke, noma isitshalo sasendlini esikhula sibheke efasiteleni elinelanga.
Ngesilinganiso sesikhathi esifushane kakhulu, i- ama-chloroplast ngaphakathi kwamaseli ezitshalo azohamba ngokushesha ekuphenduleni ushintsho ku amandla okukhanya. Ama-chloroplasts ayizingxenye eziluhlaza zamangqamuzana ezitshalo aqhuba i-photosynthesis, inqubo yokuguqula ukukhanya kwelanga kube amandla amakhemikhali. Azimile ngaphakathi kweseli, zikwazi ukusebenzisa amaprotheni ngaphakathi kolwelwesi lwazo ukuhambahamba ngaphakathi kwe-cytoplasm.
Ezimweni zokukhanya okuphansi, ama-chloroplast azosabalala ukuze athwebule inani eliphezulu lokukhanya. Kodwa-ke, ukuchayeka ngokweqile ekukhanyeni okukhanyayo kuzobalimaza, isiphetho abasigwemayo ngokuhamba okusheshayo kokuphunyuka. Ngakho-ke, ukunyakaza kwe-chloroplast ngasikhathi sinye kukhulisa ukusebenza kwe-photosynthetic ngenkathi kunciphisa ukulimala kwesithombe.
Ukuziphatha kwengilazi
Naphezu kwamashumi eminyaka ocwaningo ngalokhu kunyakaza kwe-intracellular, kusenemibuzo eminingi evulekile mayelana nendlela ama-chloroplast ahlela ngayo ndawonye. Abacwaningi baseNyuvesi yase-Amsterdam uNico Schramma, Cintia Perugachi Israëls kanye no-Maziyar Jalaal banqume ukutadisha lokhu kuziphatha ngokombono we-physics.
Iphepha labo lishicilelwe kujenali Izinqubo ze-National Academy of Sciences.
“Imiphumela yethu ikhombisa ukuthi ekukhanyeni okufiphele, ama-chloroplast enza i-monolayer ebonisa izici ezifana nengilazi. Lokhu kukhombisa ukuxhumana okumangazayo phakathi kwalokhu uhlelo lwebhayoloji kanye nomkhakha ocebile we-glass physics,” kuchaza uSchramma. Ingaphezu nje kwempahla yamafasitela, ingilazi iyisigaba sezinto esiqinile esakhiwe izinhlayiya eziminyene kodwa ezingahlelwanga kahle.
Ngokungafani nama-athomu alula (angaphili ngempela), ama-chloroplast angasebenzisa amandla ukuze azikhiqizele ukunyakaza kwawo. Ukwengeza, ama-chloroplast ayathinteka futhi ahlanganyele nendawo yawo eyingqayizivele ye-intracellular. Lokhu kwenza lesi sigaba esiyingilazi sibe uhlobo olusha olujabulisayo lwendaba "esebenzayo".
Ukuba sesimweni esiyingilazi kuyasiza ekuqinisekiseni ukuthi ukukhanya okungenzeka kakhulu kuqoqwe ngaphansi kwezimo zokukhanya okuphansi, ngoba ama-chloroplast abekwe kahle. Uma kuvezwe ku ukukhanya okukhanyayo, lesi simo esiyingilazi ngokushesha “sincibilika” sibe uketshezi lapho ama- chloroplast ahambahamba khona ngokushesha.
Eduze noguquko
Ngokulandela umkhondo nokuhlaziya ukunyakaza okuncike ekukhanyeni kwama-chloroplast ezitshalweni ze-Elodea densa, nokuqhathanisa lokhu nemodeli yezibalo esanda kuthuthukiswa, abacwaningi bathole ukuthi ama-chloroplast ashuniwe ukuze abe seduze noguquko phakathi kwesimo sengilazi nesiwuketshezi.
Uphawu olubonisa ukusondela kwalolu shintsho ukuthi ngisho nasezimweni zengilazi ezinokukhanya okuphansi, akuwona wonke ama-chloroplast ahlala anganyakazi. Njalo ngezikhathi ezithile, i-chloroplast izoqhuma ngokuzumayo endaweni yayo, yedlule abanye abambalwa ngaphambi kokuba ibambeke futhi. Kwezinye izimo, lokhu kuqhuma kokunyakaza kubangela uchungechunge lokunyakaza okuhlelekile kuma-chloroplast aseduze.
“Ukuba seduze noguquko lwengilazi kwenza ama-chloroplast ashintshele ngokushesha esigabeni esifana noketshezi ukuze agweme ukukhanya okuphumelelayo,” kuphetha uSchramma. Ngaphandle kokuhlobana kwawo kwebhayoloji, izigaba eziguquguqukayo ezincike ekukhanyeni zama-chloroplast e-Elodea densa zakha uhlelo lwemodeli oluthakazelisayo locwaningo lwesikhathi esizayo mayelana nezinto eziminyene ezisebenzayo neziphilayo.