Ib yam ntawm cov noob hlwb yog muaj nyob rau hauv lawv cov protoplasts ntawm cov kua tshwj xeeb reservoirs - vacuoles nrog cell sap. Txij li thaum nws cov ntsiab lus yog tshuaj sib txawv los ntawm cov muaj pes tsawg leeg ntawm hyaloplasm, ib daim nyias nyias hla ntawm lawv, hu ua tonoplast. Lub plhaub no nyob ib puag ncig lub vacuole ua haujlwm ntau yam: los ntawm kev tswj cov duab ntawm cov organoid nws tus kheej mus rau tswj lub xeev ntawm tag nrho cov cell.
Lo lus yog raws li ob lo lus Greek: tonos (nruj) thiab plastos (sculpted).
Definition of concept
Hauv luv luv, tonoplast yog daim nyias nyias ntawm lub vacuole uas cais nws cov ntsiab lus los ntawm protoplast ntawm cov nroj tsuag. Raws li cov yam ntxwv ntawm topography, cov qauv no yog hu ua endomembrane. Hauv cov hlwb laus, uas muaj ib qho loj (hauv nruab nrab) vacuole, lub tonoplast dhau los ua ciam teb sab hauv ntawm protoplast (plasmalemma ua haujlwm raws li sab nrauv). Yog li, cytoplasm nyob nruab nrab ntawm ob daim nyias nyias.
Hauv lwm lo lus, tonoplast yog qhov thaiv ntawm ob qhov tseem ceeb tshaj plaws ntawm cov nroj tsuag ntawm tes: protoplast thiab cell sap, kev sib cuam tshuam ntawm kev tswj hwm nws cov haujlwm tseem ceeb.
Cov yam ntxwv dav dav thiab qhov tseem ceeb ntawm tonoplast
Cov ntsiab lus ntawm lub vacuole ua lub luag haujlwm loj rau cov nroj tsuag ntawm tes. Ntau lub tebchaw tsim nyog rau kev ua haujlwm ntawm cov nroj tsuag (cov protein, ntsev, pigments, minerals, as-ham), thiab qee zaum cov khoom degradation tuaj yeem khaws cia ntawm no. Cov kua vacuolar tsim ib qho chaw tshwj xeeb hauv cov cellular nrog cov ntsiab lus tseem ceeb ntawm ntau lub tebchaw.
Cov qauv thiab kev ua haujlwm ntawm tonoplast yog qee yam zoo ib yam li cov plasmalemma. Txawm li cas los xij, yog tias tom kawg ua haujlwm raws li tus ciam teb ntawm kev sib cuam tshuam ntawm tes nrog ib puag ncig sab nraud, ces lub vacuolar membrane yog lub luag haujlwm rau cov khoom sib pauv ntawm cytoplasm thiab cell sap. Vim qhov kev sib cuam tshuam no raug tswj hwm:
- tshuaj muaj pes tsawg leeg ntawm hyaloplasm thiab vacuole;
- txheej txheem ntawm kev khaws cia lossis, hloov pauv, tso tawm cov as-ham thiab lwm yam tshuaj;
- kev xav ntawm ions hauv protoplast;
- osmotic yam ntxwv;
- turgor.
Nws feem ntau yog vim lub hauv paus vacuole uas turgor siab tshwm sim, uas yog tsim los ntawm cov dej ntws mus rau hauv nws. Cov nyhuv no ua kom cov elasticity thiab cov duab ntawm cov nroj tsuag cell.
Vim tag nrho cov haujlwm ntawm lub vacuole yog txuam nrog kev nkag thiab tawm ntawm ntau yam khoom los ntawm nws, peb tuaj yeem hais tias tonoplast yog tus qauv tseem ceeb ntawm cov organoid no, vim nws nyob hauvtag nrho cov tsheb thauj mus los tau nyob rau hauv.
Tonoplast qauv
Cov qauv ntawm lub vacuolar membrane tau kawm siv infrared spectroscopy. Cov tom kawg tau pom tias tonoplast yog ib qho lipid bilayer uas muaj ntau yam proteins sib xyaw. Ntawd yog, feem ntau, cov qauv zoo ib yam li cov plasmalemma, tab sis nyob rau theem hloov maj mam, cov membranes muaj ntau qhov sib txawv.
Tonoplast lipids yog tus cwj pwm los ntawm kev txiav txim siab nrog qhov tseem ceeb ntawm cov polar molecules, uas muab siab elasticity thiab kua zog. Daim nyias nyias muaj alpha-tocopherol, uas txiav txim siab txog kev ua haujlwm antioxidant.
Hauv daim duab hauv qab no: 1 - mesoplasm; 2 - tonoplast; 3 - vacuole.
Cov protein sib xyaw ua ke rau hauv cov tonoplast muaj ntau qib sib txawv. Kev sib raug zoo ntawm lawv thiab lipid molecules yog qhov tsis muaj zog. Cov qauv spatial ntawm vacuolar membrane proteins muaj cov ntsiab lus siab ntawm alpha-helical motifs (txog 56%).
Qhov saum npoo ntawm tonoplast yog permeated nrog pores thiab molecular thauj tshuab uas muab kev xaiv nkag ntawm cov tshuaj los ntawm protoplast mus rau hauv vacuole thiab rov qab. Cov kab nqa khoom yog tsim los ntawm ntau yam proteins sib xyaw ua ke rau hauv cov txheej txheem lipid, suav nrog porins.
Tonoplast muaj nuj nqi
Tonoplast ua haujlwm hauv qab no:
- cais - delimits cov ntsiab lus ntawm vacuole los ntawm protoplast thiab rov ua dua;
- tiv thaiv - ua kom muaj kev ncaj ncees ntawm organoid, txiav txim siab kev nyab xeebprotoplast (sib xyaw cov ntsiab lus ntawm lub vacuole nrog hyaloplasm yuav cuam tshuam kev ua haujlwm ntawm tes);
- osmotic - vim yog txoj cai ntawm kev thauj khoom ion, qee qhov concentration gradients ntawm cov khoom raug tsim los ntawm ob sab ntawm daim nyias nyias;
- transmembrane - muab kev xaiv hloov pauv ntawm ntau lub tebchaw ntawm cov ntsiab lus vacuolar thiab cov protoplast.
Qhov tseeb, nws yog cov tonoplast uas tswj cov tshuaj muaj pes tsawg leeg ntawm cov kua qaub ntawm lub vacuole thiab siv nws cov ntsiab lus rau kev xav tau ntawm tes. Tau kawg, txoj kev thauj mus los ntawm daim nyias nyias tsis ua haujlwm autonomously, tab sis txuas nrog cov txheej txheem kev tswj hwm biochemical ntawm protoplast.
