I-photosynthesis yezitshalo nezici zayo

I-photosynthesis yezitshalo inqubo eyinkimbinkimbi ye-physico-biochemical, lapho izitshalo ziguqula khona amandla kagesi entshonalanga amandla amakhemikhali asetshenziselwa ama-organic compounds. Le nqubo isekelwe ekutheni ukwakhiwa kwamakhemikhali okunciphisa okwenziwe nge-oxydation, ngenxa yalokho ama-electron adluliselwa kuma-agent anciphisa ama-donor, angama-hydrogen namanzi, kulabo abamukelayo abayi-oxidizers. Kulokhu, ama-carbohydrate akha futhi i-O2 ikhishwa ngesikhathi se-oxidation yamanzi.

I-photosynthesis yezitshalo inezinyathelo ezimbili ezilandelanayo. Isigaba sokuqala sibizwa ngokuthi ukukhanya (photochemical). Ngalesi sigaba, amandla okukhanya okulinganiselwe aguqulwa abe amandla amakhemikhali ekuxhumaneni kwama-high-energy compounds, futhi aphinde ahlaziyeke. Esigabeni sesibili, kubizwa ngokuthi ubumnyama (amandla emzimbeni), amandla avela kwamakhemikhali kanye ne-reducingant jikelele awela umjikelezo ukuze alungise futhi abuyisele i-carbon dioxide, okwenza kube nokwakhiwa kwama-carbohydrate. Indlela yokwenza i-photosynthesis ihlukanisa izigaba zokukhanya nezimnyama hhayi kuphela ngesikhathi, kodwa futhi nasesikhala. Isiteji sokukhanya sidlula ngamandla akhethekile e-thylakoid-ukuguqula izitho zangasese, kanti ukusabela okumnyama kudlula ku-stroma ye-chloroplast noma kwi-cytoplasm.

I-photosynthesis nokuphefumula kwezitshalo kusekelwe ekutheni kufakwe i -quanta ekhanyayo, lapho indima enkulu idlala khona yi-chlorophylls, i-spectrum yayo ehlanganisa indawo ebonakalayo, kanye nezingxenye zezifunda ze-infrared ne-ultraviolet eziseduze nayo. I-pigment eyinhloko yazo zonke izitshalo ezenza i-photosynthesis i-chlorophyll a. Ama-algae ahlaza, ama-mosses kanye nezitshalo ezinamapulisi ane-chlorophyll b, eyenza i-spectrum ekhanyisiwe. Ezinye izinhlobo ze-algae nazo zine-chlorophylls c no-d. Ngaphezu kwe-chlorophylls, i-carotenoids kanye ne-phycobilins nayo iyingxenye ekumuneni kokukhanya.

Ngemuva kokumiswa kokukhanya, isigaba se-photochemical siqala, lapho izici ezimbili zezinhlobo ze-I no-II (i-PS1 ne-PS2) zibamba iqhaza. I-one of the systemsystems iqukethe isikhungo sokuphendula lapho izinkokhelo zihlukaniswa khona, uchungechunge lwezokuthutha kagesi lapho ama-electron akhiphe khona, kanye neqoqo lezingxenye ezenza izinqubo zokuhlunga izithombe kanye nokuvuselelwa kwesiteshi sokuphendula. Ezikhungweni zokuphendula, amandla e-quantum amancane aguqulwa abe ngamakhemikhali, bese ama-electron ahamba ngokuya kwe-gradient ye-electrochemical potential, okuyi-chain electron transport of photosynthesis.

Uhlelo lwezindlela zohlobo lwe-II lwenza ukusabela ekuthunjweni kwamanzi, ngenxa yalokho i-oksijeni ne-proton ye-H + yenziwa. Ngokuhambisana nokuthutha kwe-photosynthetic yama-electron, inqubo ye-proton yokudluliswa kusuka ku-chloroplast kuya esifundeni se-intralithicoid kwenzeka. Njengomphumela wokuphendula, i-NADPH ne-ATP yakha, okuyinto imikhiqizo eyinhloko ye-photosynthesis. I-photosynthesis eqhubekayo yezitshalo ihlanganisa ukusabela okunokwenziwa kwe-enzymatic lapho kutholakala khona amaprotheni, ama-carbohydrate namafutha. Uma imithi yamnyama ine-carbohydrate orientation, ama-amino acids, ama- organic compounds kanye nama-proteins akhiwa.

Izinqubo ze-metabolic ezihlobo lwe-CO2 fixation zihlukaniswe zibe yi-C3-, C4- ne-CAM-photosynthesis. Ama-carbohydrate, akhiwa ngesikhathi sebumnyama se-photosynthesis, angafakwa kuma-chloroplasts njenge-starch ehlanganisiwe, avela kuma-chloroplast ukuze enze amangqamuzana amasha, futhi akhonze njengemithombo yamandla okuphendula ngokumangalisayo.

I-photosynthesis yezitshalo isebenzisa amaphesenti angu-1-2 kuphela wamandla okukhanya afakiwe. Ukuqina kwenqubo ye -photosynthetic kuthinteka ekubunjweni kokubukeka komzimba kanye nokuqina kokukhanya, izinga lokushisa, ukuphathwa kwamanzi wesitshalo kanye nokudla okumbiwa kwamaminerali, ukuhlushwa kwe-CO2 ne-O2, kanye nezinye izinto eziphathelene nokusingqongileyo.