Qhov sib txawv tseem ceeb ntawm photosystem 1 thiab photosystem 2 yog tias lub photosystem 1 muaj qhov chaw tshuaj tiv thaiv ua ke ntawm chlorophyll ib lub molecule ntawm P700 uas absorbs lub teeb ntawm lub wavelength ntawm 700 nm. Ntawm qhov tod tes, lub photosystem II muaj qhov chaw tshuaj tiv thaiv suav nrog chlorophyll ib lub molecule ntawm P680 uas absorbs lub teeb ntawm lub wavelength ntawm 680 nm.
Photosystems yog cov khoom sau ntawm chlorophyll molecules, accessory pigment molecules, proteins thiab me me organic compounds. Muaj ob lub ntsiab photosystems; photosystem I (PS I) thiab photosystem II (PS II), muaj nyob rau hauv thylakoid daim nyias nyias ntawm chloroplasts hauv cov nroj tsuag. Ob leeg ua lub teeb pom kev ntawm photosynthesis. Raws li, cov nroj tsuag tseem ceeb xav tau ob qho tib si photosystems. Nws yog vim hais tias lub stripping electrons los ntawm dej yuav tsum tau ntau zog tshaj lub teeb-activated photosystem kuv muab tau. Yog li ntawd, photosystem II tuaj yeem nqus tau luv dua wavelength (lub zog siab dua) lub teeb thiab txuas hauv tandem rau PS I, ua kom tsis muaj hluav taws xob tsis zoo.
Photosystem 1 yog dab tsi?
Photosystem I (PS I) yog ib qho ntawm ob lub photosystems uas koom nrog lub teeb pom kev ntawm photosynthesis hauv cov nroj tsuag thiab algae. Photosystem kuv nrhiav tau ua ntej lub photosystem II. Hauv qhov sib piv rau PS II, PS I muaj chlorophyll ntau dua li chlorophyll b. Tsis tas li ntawd, PS I muaj nyob rau sab nrauv ntawm thylakoid daim nyias nyias thiab tuaj yeem pom tau yooj yim dua li PS II. Tsis tas li ntawd, PS Kuv koom nrog hauv cyclic phosphorylation thiab tsim NADPH.
Ntxiv mus, muaj ob qhov tseem ceeb hauv lub photosystem xws li lub kav hlau txais xov complex (lub teeb-txiav complex ntawm pigment molecules) thiab lub chaw tshuaj tiv thaiv. Muaj li ntawm 200-300 pigment molecules nyob rau hauv lub teeb-txiav complex. Cov xim sib txawv muaj nyob rau hauv lub photosystem kom sau lub teeb thiab hloov los ntawm ib tug mus rau lwm tus thiab thaum kawg muab mus rau ib tug tshwj xeeb chlorophyll ib tug molecule ntawm cov tshuaj tiv thaiv centre. Photosystem kuv muaj ib lub chaw tshuaj tiv thaiv muaj li ntawm chlorophyll ib tug molecule ntawm P700. Nws muaj peev xwm nqus tau lub teeb ntawm wavelength 700 nm.
Daim duab 01: Lub Teeb Teeb ntawm Photosynthesis
Thaum lub teeb-txiav txim siab ntawm PS Kuv nqus lub zog thiab muab tes rau nws qhov chaw tshuaj tiv thaiv, cov chlorophyll ib qho molecule hauv qhov chaw tshuaj tiv thaiv zoo siab thiab tso tawm cov hluav taws xob hluav taws xob siab. Cov molecules siab zog no mus ntawm cov khoom siv hluav taws xob thaum tso lawv lub zog. Thaum kawg, lawv tuaj rau qhov chaw tawm tsam ntawm PS II. Thaum electrons taug kev los ntawm cov saw hlau thauj khoom, nws tsim NADPH.
Photosystem 2 yog dab tsi?
Photosystem II lossis PS II yog qhov thib ob photosystem uas cuam tshuam nrog lub teeb nyob ntawm photosynthesis. Nws muaj cov tshuaj tiv thaiv qhov chaw tsim los ntawm chlorophyll ib molecule ntawm P680. PS II absorbs lub teeb ntawm lub wavelength ntawm 680 nm. Tsis tas li ntawd, nws muaj chlorophyll b pigments ntau dua li chlorophyll a. PS II tam sim no nyob rau sab hauv ntawm thylakoid daim nyias nyias. PS II tseem ceeb vim tias photolysis ntawm dej tshwm sim nrog nws. Tsis tas li ntawd, photolysis tsim molecular oxygen uas peb ua pa. Li no, zoo ib yam li PS I, PS II kuj tseem ceeb heev rau txhua yam kab mob nyob.
Pigment molecules nqus lub teeb lub zog thiab hloov mus rau P 680 chlorophyll molecules hauv qhov chaw tshuaj tiv thaiv ntawm PS II. Li no, thaum P680 tau txais lub zog, nws tau txais kev zoo siab thiab tso tawm lub zog loj molecules. Yog li ntawd, thawj electron acceptor molecules xaiv cov electrons thiab thaum kawg xa mus rau PS I ntawm kev mus los ntawm ib tug series ntawm carrier molecules xws li cytochrome.
Daim duab 02: Photosystem II
Thaum cov hluav taws xob xa mus los ntawm cov khoom siv hluav taws xob ntawm cov hluav taws xob qis, qee lub zog tso tawm yog siv rau hauv kev sib txuas ntawm ATP los ntawm ADP los ntawm cov txheej txheem hu ua photophosphorylation. Nyob rau tib lub sijhawm, lub teeb lub zog faib cov dej molecules los ntawm photolysis. Photolysis tsim 4 dej molecules, 2 oxygen molecules, 4 protons, thiab 4 electrons. Cov khoom siv hluav taws xob no hloov cov hluav taws xob poob los ntawm chlorophyll ib lub molecule ntawm PS I. Thaum kawg, molecular oxygen evolves raws li ib tug byproduct ntawm photolysis.
Dab tsi yog qhov zoo sib xws ntawm Photosystem 1 thiab Photosystem 2?
- ob PS I thiab PS II koom nrog cov kev cuam tshuam ntawm lub teeb ntawm photosynthesis. Lawv tseem ceeb sib npaug hauv photosynthesis.
- Lawv muaj ob qhov loj xws li kav hlau txais xov thiab qhov chaw tshuaj tiv thaiv.
- Tsis tas li ntawd, lawv muaj cov pigments photosynthetic uas tuaj yeem nqus tau qhov sib txawv ntawm lub hnub ci.
- Tsis tas li, ob qho tib si muaj nyob rau ntawm cov thylakoid daim nyias nyias ntawm Granna ntawm chloroplasts.
- Tsis tas li ntawd, qhov chaw tshuaj tiv thaiv ntawm txhua qhov photosystem muaj xws li chlorophyll ib molecule.
Qhov txawv ntawm Photosystem 1 thiab Photosystem 2 yog dab tsi?
Photosystem Kuv muaj chlorophyll ib lub molecule ntawm P700 nyob rau hauv nws cov tshuaj tiv thaiv chaw thaum Photosystem II muaj ib tug chlorophyll ib tug molecule ntawm P680 nyob rau hauv nws cov tshuaj tiv thaiv chaw. Yog li, PS I absorbs lub teeb ntawm lub wavelength ntawm 700 nm thaum PS II absorbs lub teeb ntawm lub wavelength ntawm 680 nm. Yog li, peb tuaj yeem txiav txim siab qhov no yog qhov sib txawv tseem ceeb ntawm photosystem 1 thiab photosystem 2. Ob lub photosystems koom nrog lub teeb-nyob ntawm cov tshuaj tiv thaiv ntawm photosynthesis. Txawm li cas los xij, PS Kuv koom nrog hauv cyclic phosphorylation thaum PS II koom nrog hauv noncyclic phosphorylation. Yog li, nws kuj yog qhov sib txawv ntawm photosystem 1 thiab photosystem 2.
Ntxiv mus, qhov sib txawv ntxiv ntawm photosystem 1 thiab photosystem 2 yog tias PS I yog nplua nuj nyob rau hauv chlorophyll-ib pigments thaum PS II yog nplua nuj nyob rau hauv chlorophyll b pigments. Tsis tas li ntawd, ib qho tseem ceeb sib txawv ntawm photosystem 1 thiab photosystem 2 yog cov txheej txheem photolysis. Photolysis tshwm sim hauv PS II thaum nws tsis tshwm sim hauv PS I. Ib yam li ntawd, molecule oxygen hloov zuj zus los ntawm PS II thaum nws tsis tshwm sim hauv PS I. Tsis tas li ntawd, photosystem kuv muaj nyob rau sab nrauv ntawm thylakoid membranes thaum photosystem II tam sim no. nyob rau hauv lub puab nto ntawm thylakoid daim nyias nyias. Yog li, qhov no kuj yog qhov sib txawv tseem ceeb ntawm photosystem 1 thiab photosystem 2.
Hauv qab infographic ntawm qhov sib txawv ntawm photosystem 1 thiab photosystem 2 muab cov ntaub ntawv ntxiv txog qhov sib txawv no.
Summary – Photosystem 1 vs Photosystem 2
Photosystem I thiab Photosystem II yog ob lub photosystems loj uas ua rau lub teeb-nyob ntawm kev cuam tshuam ntawm photosynthesis hauv cov nroj tsuag. PS Kuv koom nrog hauv cyclic phosphorylation thaum PS II koom nrog hauv noncyclic phosphorylation. Lub chaw tshuaj tiv thaiv ntawm PS I muaj chlorophyll ib lub molecule ntawm P700 thaum lub chaw tshuaj tiv thaiv ntawm PS II muaj chlorophyll ib molecule ntawm P680. Raws li, PS I absorbs lub teeb ntawm lub wavelength ntawm 700 nm thaum PS II absorbs lub teeb ntawm lub wavelength ntawm 680 nm. Photolysis ntawm dej thiab tsim cov molecular oxygen tshwm sim koom nrog PS II thaum ob qhov xwm txheej tsis tshwm sim hauv PS I. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm photosystem 1 thiab photosystem 2.
