Kwibhayoloji, Amaxesha amaninzi siva igama elithi ribosome elinxulumene nokuguqulelwa kwemfuza, i-RNA, iiproteni kunye nabanye. Nangona kunjalo, kunzima ukuwuqonda wonke lo msebenzi ngaphandle kokucacisa malunga neekhonsepthi ezisisiseko. Kungenxa yoko le nto siza kunikezela eli nqaku ukucacisa ukuba yintoni i-ribosome.
Ukufezekisa oku, siza kuthetha kancinci malunga nomsebenzi wabo kunye neeribosomes zebhaktiriya. Ukongeza, siza kuthetha ngezinto abazivelisayo kwaye bafumaneka phi. Ukuba unomdla kwisifundo okanye ufuna nje ukwazi ukuba yintoni i-ribosome, ngokuqinisekileyo eli linqaku elifanelekileyo.
Yintoni iribosome nomsebenzi wayo?
Xa sithetha ngee-ribosomes, sibhekisa kwii-cytoplasmic organelles ezingafakwanga yimbumba ye-rRNA (ribonucleic acid) kunye neeprotein ze-ribosomal. Ngokudibeneyo benza umatshini weemolekyuli ofumaneka kuzo zonke iiseli, ngaphandle kwesidoda. Ndiyabulela kubo ukuba kunokwenzeka ukufeza ukuguqulelwa okuyimfuneko kwintetho yemfuza. Ngamanye amazwi: Ii-Ribosomes zinoxanduva lwe-protein synthesis ngolwazi oluqulathwe kwi-DNA. Oku kufika kubhalwe kwi-ribosome ngohlobo lwe-mRNA (messenger RNA).
Ngokumalunga nomsebenzi we ribosome, luguqulelo okanye ukudityaniswa kweeproteni. Ukwenza lo msebenzi, ii-ribosomes zifumana ulwazi oluyimfuneko kwi-mRNA, ukusukela Ulandelelwano lwayo lwe-nucleotide luya kugqiba ngokulandelelana kwe-amino acid yeprotein. Ngokumalunga nokulandelelana kwe-RNA, kuvela kukhutshelo lofuzo lwe-DNA. Ukugqithisela i-RNA inoxanduva lokuhambisa ii-amino acid ukuya kwi-ribosomes.
Ukuvelisa ntoni i-ribosomes?
Umsebenzi we ribosome ubalulekile kwikhowudi yemfuza. Njengoko besesitshilo ngaphambili, inoxanduva lokudityaniswa kweprotein, inkqubo ekwabizwa ngokuba yinguqulelo yemfuza. Ukwenza oku, i-ribosome ifunda ulwazi oluvela kwi-mRNA kwaye ifaka ii-amino acid zokudlulisa i-RNA kwiprotein ekhulayo ngoku. Ke ngoko, i-ribosome ivelisa iiproteni.
Ngaphambi kokuqhubeka kufuneka siyazi loo nto iiamino acid zenza iiproteni. Okwangoku ii-amino acid ezingama-20 zifunyenwe phakathi kwazo zonke izinto eziphilayo. Kwikhowudi yemfuza, iiamino acid zifakwe kwikhowudi ziikhowudi, eziphindwe kathathu zenucleotides. Kukho iikhowudi ezingama-64 ezinekhowudi yazo zonke iiamino acid kunye nemiqondiso emithathu yokumisa ukuguqulelwa. Ke ngoko ikhowudi iyawohloka kwaye iikhowudi ezininzi ezahlukeneyo zisebenzisa iamino acid efanayo.
I-Ribosome: IProtein Synthesis okanye uguqulo
Ngokubanzi, inkqubo yokuguqula iqala nge-AUG codon, enoxanduva lokufaka iikhowudi kwi-amino acid ebizwa ngokuba yimethionine. Ikhowudi ephawula ukuphela kweprotein yi-codon yokumisa. Njengakwizinto ezininzi eziphilayo, ikhowudi nganye yekhowudi ye-amino acid efanayo, ikhowudi yemfuza ithathwa njengeyendalo iphela.
Amacandelo amabini eribhosome aphuma kwiseli yeseli: Izinto ezincinci kunye neziphambili. Ezi zigcinwe kunye ziityholo. Xa uxinzelelo lwe-magnesium (Mg2+) iyancipha, omabini amacandelwana athambekele ekwahlukaneni.
Zithini i-ribosomes zebacteria?
Siza kuqala sichaze kakuhle ukuba zeziphi iibhaktheriya ngaphambi kokuthetha ngeeribosomes zazo. Njengokuba, Zizinto eziphilayo ze-prokaryotic unicellular eziphilayo, Oko kukuthi, abanayo i-nucleus. Ukufumana umbono ongcono: izinto zemvelo zebhaktiriya, ezinokuba yimolekyuli ene-DNA ejikelezwe kabini, isimahla ngaphakathi kwesytoplasm kwaye ayifakwanga kwinucleus njengoko kunjalo ngeeseli ze-eukaryotic.
Xa sijonga ibacteria phantsi kwemicroscope, zikhangeleka ngathi ziintonga, isangqa okanye iibhola. Ngaphandle kwento phantse wonke umntu ayikholelwayo, uninzi lwazo aluyongozi. Ngaphantsi kwepesenti enye yebhaktiriya ibangela izifo. Ngapha koko, zibalulekile kwindalo ekhoyo emhlabeni.
I-ribosomes yebhaktiriya iyaqhubeka nokwenza umsebenzi ofanayo: Ukuhlanganiswa kweprotheni. Kuphela, ngeli xesha, kwenzeka kwiibhaktheriya. Yinkqubo ebalulekileyo ekukhuleni kwayo.
Ukukhula kwebhakteria
Zizonke izigaba ezithathu zokukhula kwebhaktiriya ezihamba kuzo. Siza kuphawula ngazo apha ngezantsi ukuze siyiqonde ngcono indima ebalulekileyo ye-ribosome kule meko.
- Isigaba seLag / isigaba sokuziqhelanisa: Inani leebhaktiriya lifuna ixesha lokuziqhelanisa nelikwimeko entsha enika izakhamzimba eziyimfuneko ekukhuleni kwayo. Kule meko, ukukhula kuyacotha ngelixa iiseli zilungiselela ukuqala ukukhula ngokukhawuleza. Ngapha koko, kubandakanya inqanaba eliphezulu leprotein biosynthesis, apho iribosomes ingena khona.
- Isigaba esibonakalayo: Ngeli nqanaba, ukukhula kweseli kuyakhawuleza kwaye kuyabonakalisa. Izakhamzimba zenziwe ngesona santya siphezulu siphezulu kude kube sele zidiniwe, zinika indlela kwisigaba sesithathu nesokugqibela.
- Indawo yokumisa: Kwinqanaba elimileyo, iiseli zinciphisa kakhulu umsebenzi wazo wokumisa umzimba kwaye ziqale ukusebenzisa iiproteni ezingafunekiyo zeselfowuni njengomthombo wamandla. Eli lixesha lotshintsho ukusuka ekukhuleni ngokukhawuleza ukuya kwimeko yokuphendula ngoxinzelelo. Kuyo, ukubonakaliswa kwemfuza okunxulumene nokulungiswa kwe-DNA, ukuthuthwa kwezondlo kunye ne-antioxidant metabolism.
Ke, ngaphandle kwe-ribosomes, iintsholongwane azinakuqala nokukhula kwazo.
Zifumaneka phi i-ribosomes?
Kukho iindawo ezahlukeneyo apho kufumaneka khona i-ribosomes: Kwi-reticulum enobunzima be-endoplasmic, kwi-mitochondria, kwii-chloroplast, nakwi-cytosol. Nangona kunjalo, banokubonwa kuphela besebenzisa imicroscope ye-elektroni, kuba ubungakanani bazo zii-nanometer ezingama-32 kwimeko yeeseli ze-eukaryotic kunye nee-nanometer ezingama-29 kwiiseli zeprokaryotic. Xa zijongwa phantsi kwemicroscope ye-elektroni, zijikeleze imilo kwaye zixinene ngombane. Kwelinye icala, phantsi kwemicroscope ebonakalayo kuyabonakala ukuba banoxanduva lwe-basophilia yeeseli ezithile.
Ndiyathemba ukuba eli nqaku likucacisile ukuba yintoni i-ribosome kunye nomsebenzi wayo. Ihlabathi lebhayoloji kunye nemfuza likhulu kwaye izinto ezintsha ziyafunyanwa ngalo lonke ixesha. Ukuziqonda, kufanelekile ukuba ube nolwazi olusisiseko njengokwazi ukuba luyintoni uguquko lofuzo kwaye lusebenza njani.