I-photosynthesis, inkqubo apho ezinye izinto ziguqula ukukhanya kwelanga zibe ngamandla emichiza, yaziwa kakuhle. Kodwa, sisenzeko esintsonkothileyo, esibandakanya uninzi lweeproteni. Imolekyuli Chl f, Uhlobo olutsha lweklorophyll, yaziwa ngokuba nenxaxheba kwiifotosinthesisi, kodwa ngenxa yokufumanisa kwayo ngoku, indawo ekuyo nemisebenzi yayo ayiqondakali. Izazinzulu ezivela eJapan ngoku ziye zahlalutya ngokweenkcukacha iprotein complex ebandakanyeka kwifotosinthesisi kwaye bafumanisa izinto ezininzi ezintsha malunga neChl f.
Zonke izinto eziphilayo zifuna amandla ukuze zisinde, kwaye la mandla avela ngqo elangeni. Ezinye izinto eziphilayo, ezinje ngezityalo, icyanobacteria, kunye ne-algae, ziyakwazi ukuguqula ngokuthe ngqo la mandla okukhanya abe ngamandla eekhemikhali ngenkqubo ebizwa ngokuba yi "photosynthesis". Ezi zinto ze-photosynthetic ziqulathe izakhiwo ezizodwa zokulamla ifotosinthesisi, ebizwa ngokuba yi "photosystems". Zimbini iifystems ezenza ukukhanya-kokuguqulwa kwamandla, nganye nganye ineqela leeproteni kunye nee-pigment. Phakathi kwee-pigments ze-photosynthetic, i-chlorophyll yeyona nto ibaluleke kakhulu, engagcini nje ngokufumana amandla avela elangeni kodwa ikwathabatha inxaxheba kwi "electron transfer chain", indlela yeemolekyuli apho iifoto (ukusuka elangeni) ziguqulwa zibe zii-electron (ezisetyenziswayo njengomthombo wamandla). Kukho iintlobo ezahlukeneyo zeemolekyuli ze-chlorophyll, nganye inemisebenzi ethile ukusukela ekufunxeni ukukhanya nokukuguqula kube ngamandla. Ngapha koko, imolekyuli nganye yeklorofili ithatha ukukhanya kwimimandla eyahlukeneyo. Kutshanje, uhlobo olutsha lwechlorophyll ebizwa ngokuba yiChl f yafunyanwa, kodwa iinkcukacha ezinje kanye apho ikhoyo kwaye isebenza njani ihleli iyimfihlakalo kude kube ngoku.
Kwisifundo esitsha esishicilelwe kwi Nature Communications, Iqela labaphandi elikhokelwa nguNjingalwazi Tatsuya Tomo kwiYunivesithi yaseTokyo yezeNzululwazi, eJapan, kubandakanya nabaphengululi abasebenzisanayo abavela kwiYunivesithi yase-Okayama, iYunivesithi yaseTsukuba, iYunivesithi yaseKobe, kunye neRIKEN, ityhile iinkcukacha ezintsha malunga nendawo kunye nemisebenzi yeChl. f. Bafuna ukuqonda malunga nenkqubo entsonkothileyo yefotosinthesisi, njengoko ukuqonda okunzulu ngale nkqubo kunokuba nezicelo ezahlukeneyo ezizayo, njengokuphuhliswa kweeseli zelanga. Ethetha ngophononongo, uNjingalwazi Tomo uthi, “Ikhosi yokuqala yefotosinthesisi iqala xa i-photosynthesis pigment ebotshelelwe kule photochemical complex ifunxa ukukhanya. Sihlalutye ubume besakhiwo esandula ukufunyanwa sobuchwephesha, inkqubo yefoto I kunye neChl f enobuninzi bokufunxa kwicala elisezantsi lamandla okukhanya (ukukhanya okubomvu kakhulu). Ngapha koko, sihlalutye umsebenzi weChl f. "
Into ezazisaziwa ngoososayensi ukuza kuthi ga ngoku kukuba nguChl f "lubomvu krwada", oko kuthetha ukuba le molekyuli ifunxa ukukhanya okubomvu kude ukusuka esiphelweni sesibane. UNjingalwazi Tomo kunye neqela lakhe bafuna ukwemba nzulu, kwaye ngenxa yoku, bafunda i-alga apho uChl f yafunyanwa kuqala. Ngokusebenzisa ubuchwephesha obunjenge-cryo-electron microscopy, bahlalutya ubume besisombululo esiphakamileyo senkqubo yefoto kule alga ngokweenkcukacha kwaye bafumanisa ukuba i-Chl f ibekwe kumda wesistim yefotos I (enye yeendlela ezimbini zeefotosystems) kodwa ayikho in ikhonkco lokuhambisa elektroniki. Baye bafumanisa ukuba ukukhanya okubomvu kakhulu kubangela utshintsho kulwakhiwo kwinkqubo yeefoto, ezihamba nokudityaniswa kweChl f kwialgae, ebakhokelela ekubeni bagqibe kwelokuba uChl f ibangela olu tshintsho kulwakhiwo lwefotosystem I. Oku bekuchulumancisa, njengoko oku kufumanisa kungowokuqala wokuchaza ukuba ichane kangakanani iChl f iyasebenza. UNjingalwazi Tomo uthi, “Iziphumo zethu ziveze ukuba ukubonakala kuka-Chl f idityaniswe kakuhle nentetho yeefotosystem I zofuzo ezibangelwa kukukhanya okubomvu krwe. Oku kubonisa ukuba uChl f imisebenzi yokuvuna ukukhanya okubomvu krwe kunye nokwandisa ukuhanjiswa kwamandla. Sifumanise ukuba ulandelelwano lwe-amino acid yenkqubo yefoto nditshintshiwe ukuze ndikwazi ukumisa ubume beChl f. "
Ukuqonda ubunzima be-photosynthesis inezicelo ezininzi ezibalulekileyo. Umzekelo, ukulinganisa inkqubo yefotosinthesisi kwinkqubo eyenziweyo yindlela ebalaseleyo yokufumana amandla elanga kunye nokuwuguqula ube ngumbane. UNjingalwazi Tomo uyacacisa, “Malunga nesiqingatha samandla elanga awela emhlabeni kukukhanya okubonakalayo, kwaye esinye isiqingatha kukukhanya kwe-infrared. Uphando lwethu lubeka umatshini onokusebenzisa ukukhanya kumbane wamandla asezantsi, ongazange wabonwa ngaphambili. Iziphumo zethu zibonisa indlela yokuphucula ukusebenza kokudluliselwa kwamandla kwi-photosynthesis kwaye, ngokolwandiso, kunika ukuqonda okubalulekileyo kwi-photosynthesis eyenziweyo. ”
ICandelo leMicimbi yezeNkcubeko leYunivesithi yaseKobe
Malunga neYunivesithi yaseTokyo yeSayensi
IYunivesithi yaseTokyo yeSayensi (i-TUS) yiyunivesithi eyaziwayo nehlonitshwayo, kunye neyona yunivesithi inkulu kwezophando yabucala eJapan, eneekhampasi ezine kumbindi weTokyo nakwiidolophu zayo naseHokkaido. Eyasungulwa ngo-1881, iyunivesiti iye yaqhubeka igalelo ekuphuhlisweni kweJapan kwisayensi ngokubethelela uthando lwezesayensi kubaphandi, ochwepheshe kunye nootitshala.
Ngomsebenzi "Wokudala isayensi kunye netekhnoloji yophuhliso oluhambelanayo lwendalo, abantu, kunye noluntu", i-TUS yenze uluhlu olubanzi lophando ukusuka kwisiseko ukuya kwisayensi esetyenzisiweyo. Tus uye wamkela indlela ezixubeneyo kuphando kunye nokwenza uphando olunzulu kwezinye iinkalo namhlanje kubaluleke kakhulu. I-TUS yidemokhrasi apho eyona nto ibalaseleyo kwisayensi yamkelwe kwaye yondliwa. Yiyo kuphela eyunivesithi yabucala eJapan evelise iBhaso likaNobel kunye neyunivesithi yabucala kuphela eAsia ukuvelisa abaphumeleleyo beBhaso likaNobel kwicandelo lezenzululwazi yendalo.
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INTO ONOKUYITHATHA KWELI NQAKU:
- By using techniques such as cryo-electron microscopy, they analyzed the high-resolution structure of the photosystem in this alga in detail and found that Chl f is located at the periphery of photosystem I (one of the two types of photosystems) but is not present in the electron transfer chain.
- They also found that far-red light causes structural changes in the photosystem, which are accompanied by the synthesis of Chl f in the algae, leading them to conclude that Chl f causes these structural changes in photosystem I.
- Among photosynthetic pigments, chlorophyll is the most crucial one, which not only captures light energy from the sun but also participates in the “electron transfer chain”, a molecular pathway through which photons (from the sunlight) are converted into electrons (which are used as an energy source).
