Ukuphefumula kwezitshalo kwenzeka emaqenjini ezitho. Emangqamuzaneni aphi izitho zokuphefumula ezenzeka ezitshalweni?

Ukuphefumula kuhilela izinhlelo ezihambisa umzimba nge-oxygen. Ezitshalweni kufana nesilwane. Le nqubo ihlala ngehora. Ukuphefumula kwezitshalo kwenzeka emaqenjini ezitholakala endaweni yonke yamaqabunga, iziqu kanye nezimpande. Isebenzisana nawo wonke amaseli omzimba. Uma ummeleli we-flora enokuvinjelwa kwamaseli, ukugeleza kwe-carbon dioxide kuzophela. Kulesi simo, lesi sitshalo singafa.

Isizinda semlando

Ukuthi izitshalo zikhulula i-oxygen ngesikhathi sokuphefumula zalotshwa emisebenzini yesayensi ye-A.L. I-Lavoisier. Ngo-1773-1783 waqhuba ukuhlolwa. Umphumela womsebenzi wakhe kwaba ukutholakala ukuthi lapho kuvutha nokuphefumula, inani elikhulu lomoya-mpilo lithathwa. Ngesikhathi esifanayo, kukhishwa i-carbon dioxide nokushisa.

Ngokwemisebenzi yakhe, usosayensi wembula ukuthi ukuphefumula ukushisa izakhi ezithombeni eziphilayo. Kamuva lo msebenzi waqhutshwa nguJen Ingenhaus. Wafakazela ukuthi ebumnyameni, nasentshonalanga, i-carbon dioxide ixhunyiwe futhi ikhishwa umoya-mpilo. Lokhu kusho ukuthi lapho izitshalo zokuphefumula zingahle zisebenze kokubili i-CO ₂ ne-O ₂ , kuye ngokuthi ukukhanya kuhlanganyela kule nqubo noma cha.

Izifundo ezifanayo zenziwa nguH.F. USheinbain no-A.N. Bach. Ngo-1897 kwatholakala inkolelo ye- oxidation yezinto eziphilayo. Ngonyaka ofanayo uK. Engler wethule imisebenzi efanayo. Ngo-1955 O. Khayishi noG.S. U-Mason ngosizo lwezilingo uqinisekise ukuthi i-oksijeni iyisici esibalulekile sezinto eziphilayo.

Okucacile ukuphefumula kwezitshalo

Inqubo yendawo yonke ibizwa ngokuthi ukuphefumula. Kubhekwa njengengxenye ebalulekile yazo zonke izinto eziphilayo. Kukholelwa ukuthi ukuphefumula ezitshalweni kwenzeka emaqenjini ezinhlobonhlobo nezicubu ezenziwa yi-gas exchange. Uhlelo olunjalo luhlotshaniswa nokuphila, nokuphela kokuphefumula - ngokufa kwayo yonke impilo.

Ukubonakaliswa komsebenzi obaluleke kakhulu kuhlanganiswe nokusetshenziswa kwamandla. Ngesikhathi esifanayo, kukhona ukuthuthukiswa, ukukhiqiza, ukukhula, ukuhlukaniswa kwamaseli. Ama-nutrients, amanzi, ama-syntheses ahlukahlukene kanye nezinqubo zishukunyiswa futhi zithathwa. Izitho zokuphefumula zezitshalo ziyinkimbinkimbi ye-multi-link system. Izinqubo ze-oxydative ezihlanganisiwe zishintsha ukwakhiwa kwamakhemikhali ezinhlanganisela eziphilayo.

Ukuphefumula kweselula

Lokhu ukuphefumula kuyinkqubo ye-oxidative. Ihilela u-oksijini kanye nokwehla kwezakhi zomzimba ezibalulekile. Kukhona ukukhululwa kwamandla nokwakheka kwe-metabolites esebenzayo. Amaseli asetshenziselwa ukwakha izinqubo ezibalulekile ezidingekayo. Kulesi simo, ukuphefumula kwezitshalo kwenzeka emangqamuzaneni wezitho futhi kubalwa ngokusebenzisa ukulingana okufingqiwe:

C6H12O6 + 602> 6C02 + 6H20 + 2875 kJ / mol.

Amandla atholakele akhululwa ngokuphelele. Ingxenye yamandla itholakala ku-adenosine triphosphate. Ngemuva kokuqala, ukwehlukana kwamacala kagesi kusekwe phezu kwendwangu. Lesi simo sandulela umehluko ekugxilweni kwe-i-hydrogen ions, eyenziwa ezinhlangothini ezimbili zekhanda. Ukuphefumula nokudla kwezitshalo kwenzeka nge-proton gradient. Kuyinto eyinhloko yamandla, okudingekayo ukuze izinqubo ezicashile zenzeke esitokisini. Izinqubo ezinjalo zisetshenziselwa ukuhlanganisa, ukuhola, ukuhamba kwamanzi nezakhi. Esikhathini sokwakhiwa kwamakhemikhali, umehluko ongase ube khona phakathi kwemvelo kanye ne-cytoplasm. Amandla, awakwazi ukubuthelwa ku-proton gradient, ahlakazwa njengokukhanya.

Izinqubo zokuphefumula zokuCatalytic

Ukuxoshwa kwamagagasi kwenzeka ngokusiza ama-enzyme. Zibizwa ngokuthi amaprotheni catalysts. Ama-enzyme anezici ezithile:

• Ukufaneleka okukhulu kakhulu;
• Umsebenzi owandisiwe;
• Okucacile okukhulu mayelana nokuhambisa.

Ukuphefumula kanye nokudla kwezitshalo kuncike ekuhloleni kwendawo, okuyinto eguquka ngaphansi kwethonya lezici zangaphakathi nangaphandle. Kukhona umthethonqubo we-metabolism. Ezinye zezindlela ze-oxidation zihlobene nomqondo wama-electron. Izinhlobo zokuphendula kwe-oxidation:

• Ukutholwa kwama-electron;
• Ukwengeza kwe-oksijini;
• Ukususwa kwe-hydrogen;
• Ukwakhiwa kwe-compound hydrated;
• Ukususwa kwama-proton nama-electron amabili.

Ukuxoshwa kwento ethile kuhilela ukunciphisa umamukeli. Ama-enzyme anjalo abhekwa njengama-oxidoreductases. Kulesi simo, inqola yama-protons nama-elektronika kwenzeka. Bamukela umamukeli. I-enzyme yenza ukuphendula kwezokuthutha. Izinqubo ezinjalo zihlanganisa ukuphefumula kwe-aerobic ne-anaerobic.

Ukuphefumula kwe-Aerobic

Lolu hlelo lokuphefumula lubhekisela enkambisweni ye-oxidation. Lapho ukuphefumula, lesi sitshalo sithatha i-carbon dioxide, ngaleyo ndlela sikhulule umoya-mpilo. I-substrate iyanqamuka ibe amandla wezinto ezingavamile. I-substrates eyinhloko yezitshalo zokuphefumula yi-carbohydrate. Ngaphezu kwabo, ukuhlinzekwa kwamaprotheni namafutha kungadliwa.

Ukuphefumula kufaka izigaba ezimbili eziyinhloko:

1. Inqubo ye-Anoxic. Kuyo, ukwehlukana kancane kancane kwezingxenye ze-substrates kwenzeka, ukukhululwa kwama-athomu e-hydrogen nokubopha inqubo ye-coenzymes.
2. Inqubo ye-oksijeni. Lapha, ukukhanya okulandelayo okulandelayo kwama-athomu e-hydrogen kubonakala. Baya emgodini wokuphefumula futhi kancane kancane bakhiqizwa. Ngenxa yalokho, ukudluliselwa kwamagesi ku-oxygen.

Ukuphefumula kwe-Anaerobic

Ukuphefumula okunjalo kwezitshalo kwenzeka ngosizo lwezinyunyana eziphilayo ezitsheni zezitshalo. Ukuze oxidize izinto, abasebenzisi i-oksijeni yamangqamuzana. Bakudinga usawoti we-nitric, amalahle kanye ne-sulfuric acid, lapho izinqubo zesikhathi eside zishintsha zibe ama-compounds aphansi. Amandla adingekayo atholakala ngokuhlukanisa izimolekithi eziyinkimbinkimbi zezinto eziphilayo ezilula. Ukwamukelwa kokugcina kwe-elektrononi yi-carbonates, amasulful kanye ne-nitrites. I-nitric acid, i-sulfuric ne-carbonic acid iguqulwa ekunciphiseni ama-compounds.

Uhlelo lomsuka

Ingxenye ebalulekile yenqubo ukuphefumula kwezimpande zezitshalo. Ukukhula okukhulayo, abamele imifula badinga umoya omusha ozayo ohlelweni lwempande. Ukuphefumula okunjalo kwenziwa ngosizo lwe-oksijeni, ejikeleza ngama pores amakhulu.

Nge-porosity engenawo ama-capillary phakathi kwamanzi amaningi asetshenziswe isikhathi eside noma ukukhuphuka komswakama ebhodweni, inhlabathi igcwele umswakama. Phakathi nalesi sikhathi, uhlelo lwempande luhlangene nokuphefumula. Amanye ama-subspecies zezitshalo angaphefumula ngenxa ye-oxygen encibilikiswa emswakeni. Ngesikhathi esifanayo, ukugeleza kwamanzi kufanele kuhambisane noma kugeleza. Ngomswakama oqhubekayo, izimpande zabameleli be-flora aziwutholi i-oxygen edingekayo.

Ngaphansi kwezimo ezamukelekayo, lapho ukuphefumula, isitshalo sithatha i-carbon dioxide. Kodwa ngokubusa okunamandla, akukwazi ukuqhuba ukushintshaniswa kwegesi egcwele. Ukukhula kunciphisa kakhulu. Ngokuqondene ne-nitrogen, izinga le-oxygen liyancishiswa ngo-21%. Ukusetshenziswa kwemithombo yamaminerali yomhlabathi sekuphelile. Lesi sitshalo sithatha umoya, esivela emaqabungeni, sitshalo futhi sibheke isitshalo.

Incazelo yokuphefumula

Ukuphefumula kwezitshalo kwenzeka emangqamuzaneni ezitho zomzimba futhi kuyindlela eyinhloko ye-metabolism. Amandla, akhishwa ngokuphefumula, asetshenziselwa ukukhula kanye nomsebenzi wabamele abathandekayo.

Ukuphefumula kwezitshalo kuqhathaniswa ne-photosynthesis. Inqubo ihamba ngezigaba eziningana. Ezigabeni eziphakathi, kwenziwa ama-organic compounds. Zisetshenziselwa ukusabela kwemizimba. Lezi zihlanganisa ama-pentoses nama-acids e-organic, akhiwa ngesikhathi sokubola okuphefumulayo. Ngakho-ke, ukuphefumula kubhekwa njengomthombo we-metabolites.

Uhlelo lokuphefumula lubhekwa njengomhlinzeki wamandla afanayo we-NADPH ne-ATP. Izitshalo ziphefumula umoya. Kule nqubo, abamele izitshalo bakha amanzi. Lapho lesi sitshalo siphelelwa amanzi, sivikela sona ekufeni.

Ngezinye izikhathi amandla okuphefumula angakhululwa njengokushisa. Kulokhu, inqubo yokuphefumula iyoholela ekutheni kungadingekile ukusetshenziswa kwemali eyomile. Ukwandiswa kwenqubo yokuphefumula kwesitshalo ngokwayo akusebenzi kakhulu kuwo wonke amacala.