Musoro wekuti "Kuita Kwerima: Maitiro Akakosha muPhotosynthesis"
Pendauluan
Photosynthesis inzira inokosha inoitiswa nemiti, algae, nemamwe marudzi emabhakitiriya kushandura simba rechiedza kuita simba remakemikari. Maitiro aya ane matanho maviri makuru: maitiro echiedza uye maitiro erima. Maitiro echiedza, anoenderana nechiedza, anoitika muthylakoids yema chloroplast uye anogadzira ATP neNADPH. Kusiyana neizvi, maitiro erima, asingade chiedza zvakananga, anoitika mustroma yema chloroplast uye anoshandisa ATP neNADPH zvinogadzirwa nemaitiro echiedza kugadzira glucose. Kunyangwe zvichiita sezvisinganzwisisike, maitiro erima anoita basa rakakosha muhupenyu hwe ecosystems. Chinyorwa chino chichakurukura maitiro erima mu photosynthesis zvakadzama.
Maitiro Asina Kunaka uye Kutenderera kwaCalvin
Maitiro erima anowanzo nzi Calvin Cycle, yakatumidzwa zita remusayendisiti wekuAmerica Melvin Calvin, uyo, pamwe chete nevamwe vake Andrew Benson naJames Bassham, vakabudirira kutsanangura nzira iyi yekuchinja mashandiro emuviri. Calvin Cycle inoitika mu chloroplast stroma uye imhando yemaitiro emakemikari anoshandura carbon dioxide ne organic compounds kuita glucose. Maitiro aya anogona kukamurwa kuita zvikamu zvitatu zvikuru: kugadziriswa kwekabhoni, kuderedzwa, uye kugadzikiswa kwemasero matsva.
1. Kugadzika Kabhoni
Danho rekutanga mukuita kwerima ndeyekugadzika kwekabhoni. Mudanho iri, kabhoni dhayiokisijeni inosungirirwa, kana kusungirirwa, mumakemikari eorganic. Molekyu yekutanga yekugamuchira mudenderedzwa iri i ribulose bisphosphate (RuBP), compound yekabhoni shanu. Enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) inobatsira kuita kweRuBP neCO2, zvichigadzira compound yekabhoni tanhatu iyo inokamurwa pakarepo kuita mamorekuru maviri e3-phosphoglycerate (3-PGA).
2. Kuderedza
Danho rinotevera nderekudzikisa, apo mamorekuru e3-PGA anosangana nekudzikisa reaction kuti aumbe glyceraldehyde-3-phosphate (G3P). Maitiro aya anoda kuti ATP neNADPH zvigadzirwe kubva muchiedza. Kuburikidza nemaitiro akasiyana-siyana ema enzyme, 3-PGA inogamuchira boka re phosphate kubva kuATP nema electron kubva kuNADPH, zvichigadzira G3P. Mamwe mamorekuru eG3P anobva ashandiswa kugadzira glucose, nepo mamwe asara achishandiswa muchikamu chekuvandudzwa.
3. Kuvandudzwa
Chikamu chekupedzisira cheCalvin cycle ndechekuvandudzwa. Muchikamu chino, mamorekuru eG3P asingashandiswe pakugadzira glucose anosangana nemaitiro akasiyana-siyana eenzymes kuti agadzirezve RuBP, zvichiita kuti kutenderera kudzokorore. Maitiro aya anoda ATP yakawedzerwa, uye kuunganidzwa kweATP neNADPH ndiko kunokosha kuti kutenderera kurambe kuripo.
Kukosha Kwekuita Kwerima
Rimwe remabasa makuru ekuchinja kwerima kushandurwa kweCO2 kuita makemikari eorganic, zvichizopedzisira zvagadzira glucose. Maitiro aya ndiwo hwaro hwecheni yechikafu che ecosystem nekuti inopa chikafu chikuru chezvipenyu zvinozvigadzira. Uyezve, kushanduka kwerima kunobatsirawo kudzora mwero weCO2 wemhepo, izvo zvine zvazvinoreva pakuenzana kwemamiriro ekunze epasi rose. Nekufamba kwenguva, kushanduka uku kunoita basa mukuumbwa nekuchengetwa kwesimba muhupenyu hwese hwechirimwa.
Kugadzirisa uye Kugadzirisa
Kumhanya uye kushanda zvakanaka kweCalvin cycle kunogona kusiyana zvichienderana nemamiriro ekunze akadai sekupisa, simba rechiedza, uye huwandu hweCO2. Zvirimwa zvakagadzira nzira dzakasiyana-siyana dzekugadzirisa maitiro aya. Semuenzaniso, zvirimwa zveC4 neCAM zvakashanduka kuti zviite kugadzirisa kabhoni zvinobudirira pasi pemamiriro ekunze akaipisisa, akadai sekupisa kwakanyanya uye kusanaya kwemvura.
Muzvirimwa zveC4, kutanga kwecarbon fixation kunoitika mumasero emesophyll, zvichigadzira 4-carbon acids dzinozoendeswa kumasero ebundle sheath uko kunoitika Calvin cycle. Kugadziriswa uku kunobatsira kuderedza kufema kwechiedza uye kuwedzera kushanda kwephotosynthesis mumamiriro ezvinhu ane chiedza chakawanda uye mvura shoma.
Panguva iyi, zvirimwa zveCAM (Crassulacean Acid Metabolism) zvinoita rima usiku, apo stomata dzadzo dzakazaruka kuti dzigamuchire CO2. Kabhoni iyi inozochengetwa se organic acids uye inoshandiswa masikati kana chiedza chiripo uye stomata dzadzo dzakavharwa. Kugadziriswa uku kunobvumira zvirimwa zveCAM, zvakaita se cacti, kuchengetedza kushanda kwe photosynthesis uku zvichideredza kurasikirwa nemvura.
Tsvagiridzo uye Mashandisirwo
Kudzidza nezve dark reactions hakungokoshi chete pakunzwisisa hwaro hwe plant biology asiwo kune zvakunobatsira mukurima uye biotechnology. Chimwe chezvinetso mukurima kwemazuva ano kuwedzera kushanda zvakanaka kwezvirimwa zvekudya kuti zvizadzise zvinodiwa nevanhu vari kuramba vachikura pasi rose. Nekunzwisisa zvakadzama nezve dark reactions uye Calvin cycle, masayendisiti anogona kugadzira nzira dzekuwedzera kushanda zvakanaka kwe photosynthesis uye kubereka kwezvirimwa.
Imwe nzira iri kuongororwa ndeyekugadzira majini kuti pave nenzira dzekugadzirisa metabolic kubva kuzvirimwa zveC4 kuenda kuzvirimwa zveC3, izvo zvinotarisirwa kuwedzera kushanda zvakanaka kwemvura nenitrogen uye kuderedza njodzi yekufema ne photorespiration.
Uyezve, kunzwisisa kwakawedzerwa kweRuBisCO enzyme uye mashandiro ayo zvinogona kuvhura mikana yekugadzirisa kana kutsiva enzyme nemarudzi anoshanda zviri nani, izvo zvinogona kuvandudza kugona kwephotosynthesis.
Mhedziso
Kuchinja kwerima kwe photosynthesis maitiro akaomarara akakosha kuhupenyu hwepanyika. Kuburikidza neCalvin cycle, zvirimwa nezvimwe zvipenyu zvinotora mweya wemhepo zvichiishandura kuita makemikari e organic akakosha pakudya nesimba. Kunzwisisa nekushandisa mashandiro ekuchinja kwerima hakungowedzere kunzwisisa kwedu biology yemiti chete asiwo kunogonesa kufambira mberi mukurima ne biotechnology kuti zvibatsire zvakanyanya. Kukosha kwekuchinja kwerima hakugone kupfuudzwa zvakanyanya, sezvo maitiro aya anotsigira kwete hupenyu hwezvirimwa chete asiwo zvisikwa zvese zvipenyu pasi pano zvinovimba nezvirimwa kuti zviwane okisijeni nechikafu. Kuchinja kwerima chiratidzo chekukwana uye runako rwemaitiro echisikigo anotsigira hupenyu.
