Ko te taitara "Ngā Tauhohenga Pōuri: Ngā Tukanga Matua i roto i te Whakaahua-ā-Whātu"
Pendahuluan
He tukanga nui te whakaahua-ā-tinana e mahia ana e ngā tipu, e ngā rimurimu, me ētahi momo huakita hei huri i te pūngao mārama hei pūngao matū. E rua ngā wāhanga matua o tēnei tukanga: ko ngā tauhohenga mārama me ngā tauhohenga pōuri. Ko ngā tauhohenga mārama, e whakawhirinaki ana ki te mārama, ka puta i roto i ngā thylakoid o ngā chloroplasts ka whakaputa i te ATP me te NADPH. I tetahi atu taha, ko ngā tauhohenga pōuri, kāore e hiahia tika ki te mārama, ka puta i roto i te stroma o ngā chloroplasts ka whakamahi i te ATP me te NADPH i hangaia e ngā tauhohenga mārama hei whakaputa i te hukahuka. Ahakoa he mea ngaro te āhua, he mahi nui tā ngā tauhohenga pōuri i roto i te huringa ora o ngā rauropi. Ka matapakihia e tēnei tuhinga ngā tauhohenga pōuri i roto i te whakaahua-ā-tinana.
Ngā Tauhohenga Pōuri me te Huringa Calvin
Ko ngā tauhohenga pōuri e kiia ana ko te Huringa Calvin, i tapaina i muri i te kaipūtaiao o Amerika a Melvin Calvin, nāna, me āna hoa mahi a Andrew Benson rāua ko James Bassham, i whakamārama angitu i tēnei ara pākia. Ka puta te Huringa Calvin i roto i te stroma o te chloroplast, ā, he raupapa tauhohenga matū e huri ana i te hauhā waro me ngā matū waro hei hukahuka. Ka taea te wehewehe i tēnei tukanga kia toru ngā wāhanga matua: te whakapiri waro, te whakaiti, me te whakaora.
1. Te Whakapūmau Waro
Ko te taahiraa tuatahi o ngā tauhohenga pōuri ko te whakapūmau waro. I tēnei taahiraa, ka whakapūmauhia, ka herea rānei te hauhā waro o te hau ki roto i ngā pūhui waro. Ko te ngota kaiwhiwhi tuatahi i roto i tēnei huringa ko te ribulose bisphosphate (RuBP), he pūhui waro-rima. Mā te whākōkī ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) ka āwhina i te tauhohenga i waenga i te RuBP me te CO2, ka puta he pūhui waro-ono ka pakaru tonu ki ngā ngota e rua o te 3-phosphoglycerate (3-PGA).
2. Whakaitinga
Ko te wāhanga e whai ake nei ko te whakaiti, te wāhi e pāngia ai ngā ngota 3-PGA e te tauhohenga whakaiti hei hanga i te glyceraldehyde-3-phosphate (G3P). Me whai ATP me NADPH i puta mai i ngā tauhohenga mārama mō tēnei tukanga. Mā roto i tētahi raupapa o ngā tauhohenga whākōkī, ka tangohia e te 3-PGA tētahi rōpū phosphate mai i te ATP me ngā irahiko mai i te NADPH, ka puta ko te G3P. Kātahi ka whakamahia ētahi ngota G3P mō te hanga hukahuka, ko ngā toenga ka whakamahia i te wāhanga whakaora.
3. Whakahoutanga
Ko te wāhanga whakamutunga o te huringa Calvin ko te whakaoranga. I tēnei wāhanga, ka pāngia ngā ngota G3P kāore i whakamahia mō te hanganga huka e te raupapa o ngā tauhohenga whākōkī hei whakaora i te RuBP, kia taea ai te tukurua anō i te huringa. Me whai ATP tāpiri tēnei tukanga, ā, ko te kohikohinga o te ATP me te NADPH te mea nui ki te haere tonu o te huringa.
Te Hiranga o ngā Tauhohenga Pōuri
Ko tētahi o ngā mahi matua o ngā tauhohenga pōuri ko te hurihanga o te CO2 hei pūhui waro, ā, i te mutunga ka puta he hukahuka. Ko tēnei tukanga te tūāpapa o te mekameka kai o te pūnaha rauropi nā te mea he puna kai matua mō ngā rauropi autotrophic. Hei tāpiri, ka āwhina hoki ngā tauhohenga pōuri ki te whakahaere i ngā taumata CO2 o te āhuarangi, e pā ana ki te taurite o te āhuarangi o te ao. Mō te wā roa, ka whai wāhi ēnei tauhohenga ki te hanganga me te rokiroki o te pūngao puta noa i te oranga o te tipu.
Te Arotau me te Urutau
Ka rerekē pea te tere me te whai huatanga o te huringa Calvin i runga i ngā āhuatanga taiao pēnei i te pāmahana, te kaha o te mārama, me te kukū o te CO2. Kua whakawhanakehia e ngā tipu ngā momo urutaunga hei arotau i tēnei tukanga. Hei tauira, kua whanake ngā tipu C4 me CAM ki te mahi i te whakapiri waro kia pai ake te whai hua i raro i ngā āhuatanga taiao tino kino, pēnei i te pāmahana teitei me te tauraki.
I roto i ngā tipu C4, ka puta te whakapiri waro tuatahi ki roto i ngā pūtau mesophyll, ka hanga he waikawa waro-4 ka whakawhitia ki ngā pūtau pūtu paihere, ka puta ai te huringa Calvin. Ka āwhina tēnei urutau ki te whakaiti i te manawa whakaahua me te whakanui ake i te pai o te whakaahua i raro i ngā āhuatanga o te kaha o te mārama me te iti o te wai e wātea ana.
I taua wā, ka whakahaerehia e ngā tipu CAM (Crassulacean Acid Metabolism) ngā tauhohenga pōuri i te pō, i te wā e tuwhera ana ō rātou stomata ki te tango i te CO2. Kātahi ka rongoatia tēnei waro hei waikawa waro, ā, ka whakamahia i te awatea i te wā e wātea ana te mārama, ā, kua kati ō rātou stomata. Mā tēnei urutaunga ka taea e ngā tipu CAM, pērā i ngā cacti, te pupuri i te whai huatanga o te whakaahua me te whakaiti i te ngaronga wai.
Rangahau me te Whakamahinga
Ehara i te mea he mea nui te ako i ngā tauhohenga pōuri mō te mārama ki ngā kaupapa matua o te koiora tipu anake, engari he pānga mahi anō hoki ki te ahuwhenua me te hangarau koiora. Ko tētahi o ngā wero o te ahuwhenua hou ko te whakanui ake i te whai huatanga o te whakaahua o ngā hua kai hei whakatutuki i ngā hiahia o te taupori o te ao e tipu haere ana. Mā te mārama ki ngā taipitopito o ngā tauhohenga pōuri me te huringa Calvin, ka taea e ngā kaipūtaiao te whakawhanake i ngā rautaki hei whakanui ake i te whai huatanga o te whakaahua me te hua o ngā hua.
Ko tētahi huarahi e tūhuratia ana ko te hangarau ira hei whakauru i ngā ara pākia o te tinana mai i ngā tipu C4 ki ngā tipu C3, e matapaetia ana ka whakanui ake i te whai huatanga o te whakamahinga wai me te hauota, me te whakaiti i te mōrearea o te manawa whakaahua.
Hei tāpiri atu ki tēnā, mā te mārama ake ki te whākōkī RuBisCO me tana tikanga mahi ka hua ake pea ngā whai wāhitanga ki te whakarerekē, ki te whakakapi rānei i te whākōkī ki ngā momo whai hua ake, ā, ka pai ake ai te hua o te whakaahua.
Whakamutunga
He tukanga uaua ngā tauhohenga pōuri o te photosynthesis e tika ana mō te ora i runga i te Ao. Mā te huringa Calvin, ka mimitihia e ngā tipu me ētahi atu rauropi autotrophic te hauhā waro hauhā o te rangi, ka hurihia hei matū waro e tika ana mō te kai me te pūngao. Mā te mārama me te whakamahi i ngā tikanga o ngā tauhohenga pōuri, ehara i te mea ka hohonu ake tō tātou māramatanga ki te koiora tipu, engari ka taea hoki te ahu whakamua i roto i te ahuwhenua me te hangarau koiora mō ngā painga whānui. Kāore e taea te whakanui rawa i te hiranga o ngā tauhohenga pōuri, nā te mea kāore ēnei tukanga e tautoko i te ora tipu anake engari i ngā momo ora katoa o te ao e whakawhirinaki ana ki ngā tipu mō te hāora me te kai. He tohu ora ngā tauhohenga pōuri ki te tino pai me te ataahua o ngā tukanga taiao e tautoko ana i te ora.
