Chloroplast yog cov txheej txheem membrane uas photosynthesis tshwm sim. Cov txheej txheem no hauv cov nroj tsuag siab dua thiab cyanobacteria tau tso cai rau lub ntiaj teb kom muaj peev xwm txhawb nqa lub neej los ntawm kev siv cov pa roj carbon dioxide thiab ntxiv cov pa oxygen ntxiv. Photosynthesis nws tus kheej tshwm sim hauv cov qauv xws li thylakoids. Cov no yog cov membrane "modules" ntawm chloroplasts, nyob rau hauv uas proton hloov mus, dej photolysis, qabzib thiab ATP synthesis coj qhov chaw.
Cov qauv ntawm cov nroj tsuag chloroplasts
Chloroplast yog hu ua ob-membrane cov qauv uas nyob hauv cytoplasm ntawm cov nroj tsuag thiab chlamydomonas. Nyob rau hauv sib piv, cyanobacterial hlwb nqa tawm photosynthesis nyob rau hauv thylakoids, thiab tsis nyob rau hauv chloroplasts. Qhov no yog ib qho piv txwv ntawm cov kab mob uas tsis tau tsim kho uas muaj peev xwm muab nws cov khoom noj khoom haus los ntawm photosynthesis enzymes nyob rau ntawm protrusions ntawm cytoplasm.
Raws li nws cov qauv, chloroplast yog ob lub cev ua haujlwm hauv daim ntawv ntawm npuas. Lawv muaj nyob rau hauv loj tus xov tooj nyob rau hauv lub hlwb ntawm photosynthetic nroj tsuag thiab tsim tsuas yog nyob rau hauv cov ntaub ntawv ntawmtiv nrog ultraviolet lub teeb. Nyob rau hauv lub chloroplast yog nws cov kua stroma. Nyob rau hauv nws muaj pes tsawg leeg, nws zoo li hyaloplasm thiab muaj 85% dej, nyob rau hauv uas electrolytes yog yaj thiab proteins raug tshem tawm. Lub stroma ntawm chloroplasts muaj thylakoids, cov qauv uas lub teeb thiab tsaus theem ntawm photosynthesis ncaj qha.
Chloroplast hereditary apparatus
Tom ntej mus rau thylakoids muaj cov granules nrog cov hmoov txhuv nplej siab, uas yog cov khoom ntawm polymerization ntawm qabzib tau txais los ntawm photosynthesis. Dawb hauv cov stroma yog plastid DNA nrog rau cov ribosomes tawg. Yuav muaj ntau DNA molecules. Ua ke nrog biosynthetic apparatus, lawv yog lub luag hauj lwm rau kev kho cov qauv ntawm chloroplasts. Qhov no tshwm sim yam tsis siv cov ntaub ntawv keeb kwm ntawm lub cell nucleus. Qhov tshwm sim no tseem ua rau nws tuaj yeem txiav txim siab qhov muaj peev xwm ntawm kev ywj pheej loj hlob thiab kev tsim tawm ntawm chloroplasts nyob rau hauv rooj plaub ntawm kev faib cell. Yog li ntawd, chloroplasts, nyob rau hauv ib co respects, tsis nyob ntawm seb lub cell nucleus thiab sawv cev, raws li nws yog, ib tug symbiotic underdeveloped kab mob.
qauv ntawm thylakoids
Thylakoids yog disc-puab membrane cov qauv nyob rau hauv lub stroma ntawm chloroplasts. Nyob rau hauv cyanobacteria, lawv tag nrho nyob rau ntawm invaginations ntawm cytoplasmic membrane, vim lawv tsis muaj chloroplasts ywj siab. Muaj ob hom thylakoids: thawj yog thylakoid nrog lub lumen, thiab qhov thib ob yog ib qho lamellar. Lub thylakoid nrog lub lumen yog me me nyob rau hauv txoj kab uas hla thiab yog ib tug disc. Ob peb thylakoids teem vertically tsim ib grana.
Lamellar thylakoids yog daim hlau dav uas tsis muaj lumen. Tab sis lawv yog lub platform uas ntau cov nplej txuas nrog. Nyob rau hauv lawv, photosynthesis xyaum tsis tshwm sim, vim hais tias lawv yuav tsum tau tsim ib tug muaj zog qauv uas yog resistant rau mechanical puas rau lub cell. Nyob rau hauv tag nrho, chloroplasts tuaj yeem muaj li ntawm 10 txog 100 thylakoids nrog lub lumen muaj peev xwm ntawm photosynthesis. Cov thylakoids lawv tus kheej yog cov qauv tsim lub luag haujlwm rau photosynthesis.
Lub luag haujlwm ntawm thylakoids hauv photosynthesis
Cov tshuaj tiv thaiv tseem ceeb tshaj plaws ntawm photosynthesis tshwm sim hauv thylakoids. Thawj yog lub photolysis splitting ntawm cov dej molecule thiab cov synthesis ntawm oxygen. Qhov thib ob yog kev thauj mus los ntawm proton los ntawm daim nyias nyias los ntawm cytochrome b6f molecular complex thiab electrotransport saw. Tsis tas li ntawd nyob rau hauv thylakoids, lub synthesis ntawm high-zog ATP molecule tshwm sim. Cov txheej txheem no tshwm sim nrog kev siv cov proton gradient uas tau tsim ntawm thylakoid membrane thiab chloroplast stroma. Qhov no txhais tau hais tias cov haujlwm ntawm thylakoids ua rau nws muaj peev xwm paub txog tag nrho lub teeb theem ntawm photosynthesis.
Lub teeb theem ntawm photosynthesis
Ib yam tsim nyog rau lub hav zoov ntawm photosynthesis yog lub peev xwm los tsim lub peev xwm ntawm daim nyias nyias. Nws yog ua tiav los ntawm kev hloov ntawm electrons thiab protons, vim yog tsim H + gradient, uas yog 1000 npaug ntau dua hauv cov mitochondrial membranes. Nws yog qhov zoo dua los coj cov electrons thiab protons los ntawm cov dej molecules los tsim cov khoom siv hluav taws xob hauv lub cell. Nyob rau hauv qhov kev txiav txim ntawm ib qho ultraviolet photon ntawm thylakoid daim nyias nyias, qhov no yuav muaj. Ib tug electron yog khob tawm ntawm ib tug dej molecule, uastau txais ib qho txiaj ntsig zoo, thiab yog li ntawd, txhawm rau nruab nrab nws, nws yog qhov yuav tsum tau tso ib qho proton. Raws li qhov tshwm sim, 4 dej molecules tawg rau hauv electrons, protons thiab tsim oxygen.
Cov saw ntawm cov txheej txheem photosynthesis
Tom qab photolysis ntawm dej, daim nyias nyias yog recharged. Thylakoids yog cov qauv uas tuaj yeem muaj acidic pH thaum hloov cov proton. Lub sijhawm no, pH hauv stroma ntawm chloroplast yog me ntsis alkaline. Qhov no ua rau muaj peev xwm electrochemical uas ua rau ATP synthesis ua tau. Adenosine triphosphate molecules tom qab ntawd yuav raug siv rau kev xav tau lub zog thiab lub sijhawm tsaus ntuj ntawm photosynthesis. Tshwj xeeb, ATP yog siv los ntawm lub xov tooj ntawm tes los siv cov pa roj carbon dioxide, uas yog ua tiav los ntawm nws cov condensation thiab synthesis ntawm qabzib molecules raws li lawv.
Nyob rau theem tsaus ntuj, NADP-H+ raug txo rau NADP. Nyob rau hauv tag nrho, lub synthesis ntawm ib tug qabzib molecule yuav tsum tau 18 ATP molecules, 6 carbon dioxide molecules thiab 24 hydrogen protons. Qhov no yuav tsum tau photolysis ntawm 24 dej molecules siv 6 carbon dioxide molecules. Cov txheej txheem no tso cai rau koj tso tawm 6 oxygen molecules, uas tom qab ntawd yuav siv los ntawm lwm cov kab mob rau lawv cov kev xav tau ntawm lub zog. Nyob rau tib lub sijhawm, thylakoids yog (hauv biology) piv txwv ntawm cov qauv membrane uas tso cai rau kev siv lub hnub ci zog thiab lub peev xwm transmembrane nrog pH gradient los hloov lawv mus rau hauv lub zog ntawm cov khoom siv tshuaj.
