Ngaphakathi kwebhayoloji kukho isebe elibizwa ngokuba yi-cell biology, elalisaziwa njenge-cytology, elijongene nokufundwa kweeseli. Ezi microorganisms ezenza zonke izinto eziphilayo baneempawu zabo kunye nolwakhiwo, kuxhomekeke kuhlobo abalulo. Njengokuba sisifundo esibanzi kwaye sinzima, siza kugxila namhlanje kwinxalenye yezityalo: udonga lweseli yesityalo.
Ukuba unomdla kwisifundo kwaye ufuna ukwazi ngakumbi malunga neli nxalenye lincinci leeseli zezityalo, ndincoma ukuba uqhubeke nokufunda. Siza kuchaza ukuba yintoni umsebenzi weseli yesityalo ngaphambi kokuthetha ukuba yintoni udonga lweseli yesityalo. Emva koko siza kuthetha ngobume bayo kunye nezinto zayo.
Yintoni umsebenzi weseli yesityalo?
Ngaphambi kokuba sithethe ngodonga lweseli yesityalo, masiqale sicacise umsebenzi weeseli zezityalo. Luhlobo lweseli ye-eukaryotic eyenza izicwili zezityalo kwezo zinto ziyinxalenye yobukumkani IPlantae.
Zinokufana okuthile kwiiseli zezilwanyana. Kuzo zombini iimeko, ziiseli ze-eukaryotic eziqulathe umahluko wokwahlulahlula, i-cytoplasm, inwebu kunye nolwazi lofuzo. ikwabizwa ngokuba yi-DNA. Nangona kunjalo, kukho umahluko obaluleke kakhulu phakathi kweentlobo ezimbini zeeseli. Imifuno iyakwazi ukwenza ifotosinthesize. Yinkqubo yemichiza apho izityalo zisebenzisa amandla okukhanya ukwenza izinto eziphilayo, ngaloo ndlela zikhupha ioksijini.
Luthini udonga lweseli yesityalo?
Xa sithetha ngodonga lweseli yesityalo, sithetha umaleko ongqongqo kunye nonqabileyo oxhasa imikhosi eyahlukeneyo ye-osmotic kunye nokukhula. Indawo ekuyo ingaphandle leembumba zeplasma kwiiseli zezityalo, kunye nefungi, ibhaktiriya, i-archaea kunye ne-algae. Umsebenzi wodonga ngu khusela umxholo weseli, unike ukuqina kwaye uchaze ubume bezityalo. Ukongeza, isebenza njengomlamli phakathi kweseli kunye nokusingqongileyo.
Luyintoni ulwakhiwo lodonga lweseli yesityalo?
Udonga lweseli yesityalo linamalungu amathathu asisiseko ngokobume bawo. Siza kuphawula ngazo apha ngezantsi:
- Udonga lokuqala
Ihlala iphakathi kwe-100 kunye ne-200 yeenanometer ubukhulu kwaye ifumaneka kuzo zonke iiseli zezityalo. Ludonga olwenziwe kukuqokelelwa kwezinto ezintathu okanye ezine zeeselulose microfibrils. Ilungelelaniswe ngokugqibeleleyo nokukhula kweseli enkosi kwii-microfibrils, njengoko ezi zilayida phakathi kwazo, zivelisa ukwahlukana okude. - Udonga lwesibini
Nangona iqhelekile, ayikho kuzo zonke izityalo. Udonga lwesibini ngumaleko omelene nenwebu yeplasma. Ineselulosi eninzi, i-lignin kunye ne-suberin. Ukongeza, ayinakhubazeka kwaye ayivumeli iiseli ukuba zikhule. Nje ukuba ukukhula kweseli kufike esiphelweni, kwakhiwa udonga lwesibini. Ngokubanzi, ityebile kakhulu kunodonga oluphambili kwizicubu zomthi. - I-lamella ephakathi
I-lamella esembindini ngumaleko omsebenzi wawo kukujoyina iindonga zokuqala. Amacandelo ayo aphambili yi-pectin kunye ne-hemicellulose.
Ukwakhiwa kodonga lweseli yesityalo
Ngokubhekisele kubume bodonga lweseli yesityalo, luyahluka ngohlobo lweseli kunye namaqela ahlukeneyo etaxonomic. Ngokwesiqhelo, Yenziwe ngumnatha owenziwe ziicarbohydrate, iiproteni, kunye neephospholipids. Zonke zingene kwimatriki ye-gelatin, enokuthi ke yenziwe ngamanye amaproteni kunye neecarbohydrate.
Iicarbohydrate
Iselulosi lelona candelo liphambili kudonga lweseli yesityalo. Yifibrillar polysaccharide ecwangciswe kwii-microfibrils. Phakathi kwe-15% kunye ne-30% yobunzima obomileyo beendonga zeeseli zezityalo zihambelana nale biomolecule yendalo. Ngokumalunga ne-cellulose microfibrils, ezi ziboshwe zi-non-fibrillar carbohydrate, ebizwa ngokuba yi-hemicellulose.
Kukho elinye icandelo elibaluleke kakhulu kudonga lweseli yesityalo: iPectin. Le polysaccharide engeyo-fibrillar ityebile kwi-D-galacturonic acid ene-hydrated kakhulu kwaye i-branching yayo yahlukile. I-pectin matrix inoxanduva lwe-porosity yodonga. Ukongeza, ibonelela ngeefillers ezinomsebenzi wokulawula i-pH.
Iprotein
Elinye icandelo lodonga lweseli yesityalo ziiprotein zesakhiwo. Ezi zihlala zityebile kwi-amino acid enye okanye ezimbini, zine-glycosylated kwaye zinemimandla enokulandelelana okuphindayo. Uninzi lwezi proteni lunesakhiwo se-fibrillar esingafakwanga ngenxa ye-covalent bond phakathi kwabo okanye nee-carbohydrate. Namhlanje siyazi ukuba iiproteni zolwakhiwo ziyaqokelelana kudonga lweseli yesityalo kumanqanaba ahlukeneyo ophuhliso kunye nokuphendula kwiimeko ezahlukeneyo zoxinzelelo. Ezi ziiproteni ezakhiweyo zodonga lweseli yesityalo:
- Ii-HRGP: Iiproteni ezityebileyo zeHydroxyproline, extensins
- Ii-PRP: Iiproteni ezityebile ngeproline
- Ii-GRP: Iiproteni ezityebileyo zeGlycine
- IiAGPs: Iiproteni zityebile kwii-arabinogalactans
Ngaphakathi kwenethiwekhi yeeproteni kunye neepolysaccharides, kukwakhona ezininzi Iiproteni ezinyibilikayo:
- Ii-enzyme ezinxulumene nokwenziwa kwezondlo, ezinje ngeglucosidase.
- Ii-enzymes ezinxulumene nemetabolism yodonga. Umzekelo: Xyloglucanotransferases, peroxidases, laccases
- Iiproteni ezinxulumene nezokhuseleko
- Iiproteni zothutho
Iipolym
Kukho nezinye iipolymers eziyinxalenye yokwakhiwa kodonga lweseli yesityalo. Emva kweselulosi, elona candelo lininzi yi-lignin. Yipolymer eqinileyo e-amorphous esisiphumo somanyano lwe-phenylpropyl alcohol kunye neeasidi ezahlukeneyo. Ngokwesiqhelo iqokelela kwiindonga zesekondari. Nangona kunjalo, ngamanye amaxesha banokuvela kwi-lamella esembindini yezihlunu ezifileyo okanye ze-necrotic.
I-Cutin kunye ne-suberin zezinye iipolym zodonga lweseli. Ezi zenziwe ngee-fatty-chain chain fatty ezibophelelanayo zenza inethiwekhi engqingqwa, enamacala amathathu. Zombini iipolymers zihlala ziqokelela kwiindonga zesekondari, kodwa zinokubonakala nakwiindonga eziphambili ngendlela ekhethekileyo.
I-Wax zihlala zigqityiwe. Oku akuboneleli ngqongqo, ewe, ukunganyanzeleki kwamanzi. I-Cutin kunye ne-suberin ikwabonelela ngokuthintela ukungangeni manzi, kodwa hayi kangako.
Kwibhayoloji ngokubanzi, iiseli lilizwe liphela elisaphandwayo nanamhlanje. Sithethe kuphela ngenxalenye yeeseli zezityalo apha, kodwa kuninzi okunokufundwa.