Biospheric dab. Lub nitrogen voj voog nyob rau hauv cov xwm

Ib tug tshuaj caij nrog atomic tooj xya yog denoted los ntawm N (Nitrogenium). Nws lub npe - "Zot" - los ntawm lub Greek txhais tau tias "tsis muaj sia". Qhov no lub sij hawm, ib tug kev tshawb xav ntawm nws keeb kwm, twb npaj siab nyob rau hauv 1787 Antuanom Lavuaze xyoo, es tsis txhob ua ntej "phlogisticated", "puas" thiab cov huab cua "mefitichesky". Nws yog ces hais tias ib tug pab pawg neeg ntawm Fabkis zaum, nyob rau hauv uas Lavoisier yog nquag muab kev koom tes, koom nyob rau hauv txoj kev loj hlob ntawm cov tshuaj nomenclature hauv paus ntsiab lus. Txawm ces, nws tau pom nitrogen khoom ntiag tug tsis them nyiaj yug tej combustion los yog respiration.

Raws li lwm version lo lus "nitrogen" tsis invented los ntawm Lavoisier thiab nws cov npoj yaig. Nws tshwm sim ntau nyob rau hauv lub alchemical ntaub ntawv ntawm qhov kaj ntug ntawm cov Nrab Hnub nyoog los piav qhov thiaj li hu ua "tus thawj kws hlau khoom", thiab nws twb ntaus nqi mus rau tej nuj nqis ntau los yog tsawg, thiab cov khoom "alpha thiab omega" ntawm txhua yam.

Nyob rau hauv cov xwm, lub nitrogen tej zaum yuav tam sim no raws li ib tug yooj yim tshuaj ntawm lub mis N2, nws yog txaus inert roj yog tsis tau saj, xim thiab tsw. Peb plaub ntawm lub ntiaj teb huab cua muaj nitrogen. Qhov no lub caij plays ib tug tseem ceeb heev luag hauj lwm nyob rau hauv lub neej ntawm cov nroj tsuag thiab tsiaj txhu. Nyob rau hauv nyob tus yeees ntawm cov nqaijrog, nws feem pua yog 16-18% los ntawm ceeb thawj. Nws kuj yog ib feem ntawm cov qauv ntawm cov nucleic acids, nucleoproteins, amino acids, chlorophyll, hemoglobin. Nyob rau hauv nyob hlwb los ntawm tus xov tooj ntawm nitrogen atoms yog hais txog 2%, thiab ib tug loj feem ntawm no tivthaiv nce mus 2.5%. Caij N Qib plaub nyob rau hauv qhov tseem ceeb rau lub yooj yim cov ntsiab ntawm cov organic Science News for KIDS - hydrogen, carbon, thiab oxygen.

Yeej lub nitrogen voj voog nyob rau hauv cov xwm raws li nyob rau hauv cov tshuaj tshua nyob hauv cov huab cua. Cov lawv yuav yeej los ntawm oxidation. Tsis tas li ntawd muaj ntau yam pauv kev faib ua feem ntawm lub nitrogen kev sib tshuam noj tshuaj nyob rau hauv lub biosphere. Main N2 nyob rau hauv cov xwm - nws yog cov cua. Thiab cov nroj tsuag ua si ib qho tseem ceeb luag hauj lwm, nyob rau hauv qhov tseeb, lawv yuav pib lub nitrogen voj voog nyob rau hauv cov xwm. Cov muaj ntawm peb ntiaj chaw khiav dej num raws li ib tug protein synthesis. Raws li ntaub ntawv siv nitrates uas yog nyob rau hauv cov av. Yog qhov uas cov natural nitrate nitrogen yog aspirated thiab ammonium ntsev. Lub mechanism hloov ib tug yooj yim tshuaj nyob rau hauv daim ntawv muaj rau assimilation los ntawm cov nroj tsuag, hu ua nitrogen fixation.

Muaj ob tsevneeg nitrogen percolation mechanism. Nyob rau hauv thawj embodiment, ib tug tej yam muaj pes tsawg tus rau lub sij hawm xob ntswg ntawm nitrogen oxides. Kua nyob rau hauv dej, lawv ntxias cov tsos ntawm nitric acid, uas muab sawv mus rau lub tsos ntawm cov av nitrates. Nyob rau hauv lub thib ob embodiment, muaj yog tsim ntawm ammonia. Nws ua kab mob rau hauv nitrates, lawv feem ntau yog nyob rau hauv lub hauv paus nodules ntawm tuberous nroj tsuag. Ntau, no mechanism yog hu ua nitrification.

Tuag cog ua mus rau tsim ntawm ammonium tebchaw. Saum toj no lawv khiav lag luam cov kab mob, transforming lawv mus rau hauv nitrate nitrogen thiab rov qab mus rau lub ntuj kaaj quas lug. Fixation, nitrification thiab denitrification ntawm nitrogen - Cheebtsam ntawm ib tug complex mechanism, nqa lub nitrogen voj voog nyob rau hauv cov xwm. Tsav no yog hais tias muaj yog ib tug pauv ntawm cov nitrogen fixation thiab denitrification.

Nitrogen fixation tshwm sim thaum cog metabolize nitrogen tebchaw los ntawm huab cua, nyob rau hauv tus txheej txheem no muab kev koom tes ntau cov kab mob thiab cyanobacteria. Cov khoom kev kho nitrogen yog ammonia, nitrates los yog nitrites.

Lub nitrogen voj voog nyob rau hauv cov xwm nrog rau txoj kev hloov mus rau lub kauj ruam tom ntej yog tawm nitrification ntawm fixation. Tam sim no ammonia kis mus rau hauv nitrates thiab nitrites. Thaum lub sij hawm denitrification xaus nitrogen voj voog nyob rau hauv cov xwm, cov nitrates decompose rau nitrogen. Active kev koom tes nyob rau hauv tus txheej txheem ntawm kev noj Pseudomonas, Bacillus kab mob thiab lwm yam kab mob.

Thaum lub sij hawm denitrification zaum yuav tshwm sim ob peb intermediates. Qhov tseem ceeb tshaj ntawm lawv - cov pa roj nitrous oxide, ib tug tsev cog khoom roj yog ruaj khov.

Nthuav cov ntsiab lus, nws yog tsim nyog los nkag siab txog lub ntsiab lus ntawm lub tswv yim assimilation thiab mineralization. Assimilation yog ib tug txheej txheem ntawm txoj kev hloov ntawm inorganic nitrogen nyob rau hauv nws cov organic daim ntawv. Nyob rau hauv mineralization yog meant organic nitrogen compound mus hloov inorganic. Antagonists assimilation thiab mineralization yog ib qho tseem ceeb daim ntawv hloov dua siab tshiab tshuaj uas tshwm sim thaum lub sij hawm nitrogen voj voog nyob rau hauv cov xwm.

Kev nthuav qhia ntawm daim ntawv qhia nyob rau hauv no feem ntau ntse nqa tawm siv cov ntxhuav thiab cov kab kos.