Mosebetsi oa cytoplasm ke ofe ka protheine biosynthesis? Tlhaloso, tshebetso le mesebetsi

Sele ea ntho leha e le efe e entsoeng ke fektheri e le 'ngoe e kholo bakeng sa tlhahiso ea lik'hemik'hale. Ho na le mekhoa ea ho iphetola ha likokoana-hloko tsa lipids, nucleic acid, lik'habohaedreite 'me, ho hlakile, liprotheine. Liprotheine li phetha karolo e kholo bophelong ba sele, hobane li etsa mesebetsi e mengata: enzymatic, signal, structural, protective and others.

Likokoana-hloko tsa protheine: tlhaloso ea mokhoa ona

Ho hahoa ha limolek'hule tsa protheine ke mokhoa o rarahaneng oa mehato e mengata e hlahang tlas'a tšusumetso ea palo e kholo ea li-enzyme le ho ba teng ha mehaho e itseng.

Senyesemane sa protheine leha e le efe e qala mokokotlong. Boitsebiso bo mabapi le sebopeho sa molek'hule bo tlalehiloe DNA ea sele, eo e baloang ka eona. Hoo e ka bang leha e le efe ea liphatsa tsa lefutso e kenyelletsa e le 'ngoe feela, e leng eona feela molek'hule ea protheine.

Mosebetsi oa cytoplasm ke ofe ka protheine biosynthesis? 'Nete ke hore cytoplasm ea seleng ke "letamo" la li-monomers tsa lintho tse rarahaneng, hammoho le mehaho e ikarabellang bakeng sa tsela ea protheine ea pele. Hape, tikoloho ea ka hare ea seleng e na le li-acidity le li-content tsa kamehla, tse nang le karolo ea bohlokoa likarolong tsa lik'hemik'hale.

Phetoho ea limela tsa protheine e etsahala ka mekhahlelo e 'meli: ke phetolelo le phetolelo.

Phetolelo

Sethala sena se qala mokokotlong oa sele. Mona, nucleic acids tse kang DNA le RNA (deoxy- and ribonucleic acid) li phetha karolo ea bohlokoa. Li-eukaryot, karolo ea transcriptional ke transcripton, 'me ka prokaryotes mokhatlo o joalo oa DNA o bitsoa oponon. Phapang pakeng tsa phetolelo ea prokaryotes le eukaryotes ke hore oponon ke sebaka sa molek'hule ea DNA e kenyelletsang limolek'hule tse 'maloa tsa protheine ha tlaleho e e-na le boitsebiso bophatseng bo le bong feela ba protheine.

Mosebetsi o ka sehloohong oa seleng sethaleng sa phetolelo ke ho qaptjoa ha tlhahisoleseding ea RNA (mRNA) ka matheba a DNA. Bakeng sa sena, enzyme e kang RNA polymerase e kena mokokotlong. E kenya letsoho ho qaptjoa molek'hule e ncha ea mRNA, e tlatsanang le sebaka sa deoxyribonucleic acid.

Bakeng sa liphetoho tse ngotsoeng ka katleho, ho ba teng ha lintlha tsa ho ngolisa hoa hlokahala, tse boleloang hape ke tlhaloso ea TF-1, TF-2, TF-3. Mehaho ena e rarahaneng ea liprotheine e kenyeletsa ho kopanya RNA polymerase ho ea khothalletsang molek'hule ea DNA.

Ho sebelisoa motsoako oa mRNA ho fihlela polymase e fihla sebakeng se senyehileng sa transcripton, se bitsoang terminator.

Motho ea sebetsang, joaloka sebaka se seng sa ts'ebetso ea transcripton, o ikarabella ho thibela ho ngolisoa ha mantsoe kapa, ho bapala, ho potlakisa mosebetsi oa RNA polymerase. Boikarabello ba ho laola mosebetsi oa li-enzyme tsa phetolelo ke liprotheine-inhibitor tse khethehileng kapa liprotheine tsa activator, ka ho latellana.

Ho lahla

Ka mor'a hore mRNA e thehoe ka har'a mokokotlo oa seleng, e kena ka cytoplasm. Ho arabela potso mabapi le karolo ea cytoplasm ka protheine biosynthesis, ho bohlokoa ho senya ka ho qaqileng qetello ea molek'hule ea nucleic acid sethaleng sa phetolelo.

Phetolelo e etsahala ka mekhahlelo e meraro: ho qalisoa, ho arohana le ho felisoa.

Ntlha ea pele, mRNA e tlameha ho ikamahanya le li-ribosomes. Li-Ribosomes li na le mekhoa e nyenyane e se nang leseli ea sele, e nang le likaroloana tse peli: tse nyane le tse kholo. Ntho ea pele, ribonucleic acid e hokahane le karoloana e nyenyane, e ntan'o koala mohaho oohle oa phetolelo e le hore mRNA e ka hare ho ribosome. Ha e le hantle, sena se felisa sethaleng sa qalo.

Mosebetsi oa cytoplasm ke ofe ka protheine biosynthesis? Ntlha ea pele, ena ke mohloli oa amino acid - e leng li-monomers tse kholo tsa protheine leha e le efe. Ha sethaleng sa boithaopo, ho hahoa butle-butle ha moketeng oa polypeptide ho hlaha, ho qala ka methionine ho qala codon, moo li-amino acid tse setseng li kenngoa teng. Codon tabeng ena ke lisele tsa nucleotide tsa mRNA tse kenyang e 'ngoe ea amino acid.

Nakong ena mofuta o mong oa ribonucleic acid - ho tsamaisa RNA, kapa tRNA - ho amana ho sebetsa. Ba na le boikarabello ba ho tsamaisoa ha amino acid ho complex complex of ribosomes le mRNA ka ho thehoa ha metsoako ea aminoacyl-tRNA. Ho amoheloa ha tRNA ho hlaha ka ho kopanngoa ho tlatsanang ha anticone ea molelek'hule ena le codon mRNA. Kahoo, amino acid e fetisetsoa ho ribosome 'me e kopantsoe le ketane e entsoeng ka polypeptide.

Ho felisoa ha phetolelo ho etsahala ha libaka tsa codon tse emeng li fihla mRNA. Li-codon tsena li jara boitsebiso bo mabapi le bofelo ba peptide synthesis, ka mor'a moo mochine oa ribosome-RNA o senngoa, 'me mohaho o ka sehloohong oa protheine e ncha o kenella cytoplasm bakeng sa liphetoho tse eketsehileng tsa lik'hemik'hale.

Mokhoa oa ho fetolela o ne o akarelletsa lintlha tse khethehileng tsa protheine ea ho qaleha ha IF le maemo a ho arola EF. Li na le mefuta e sa tšoaneng, 'me mosebetsi oa tsona ke ho tiisa hore ho na le li-RNA tse nang le li-sub-ribosomal tse nepahetseng, hammoho le ho qalisoa ha moketeng oa polypeptide ka boeona nakong ea bohato ba ho itlhakisa.

Karolo ea cytoplasm ke efe ka protheine biosynthesis: ka bokhutšoanyane ka likarolo tse kholo tsa biosynthesis

Ka mor'a hore mRNA e tsoe ka har'a mokokotlo oa ka hare ho sele, molek'hule e tlameha ho theha mohaho o tsitsitseng oa phetolelo. Ke likarolo life tsa cytoplasm e lokelang ho ba teng sethaleng sa phetolelo?

1. Ribosomes.

2. Amino acid.

3. tRNA.

Li-amino acid - li-monomers tsa liprotheine

Ho etsa li-protein chain, ho ba teng ka cytoplasm ea likaroloana tsa moralo oa li-peptide molek'hule - amino acid. Lintho tsena tse tlaase tsa limolek'hule tse nang le lisele tsa tsona li na le li-amino sehlopha NH2 le libaka tse nang le masapo a COOH. Karolo e 'ngoe ea molek'hule - e kholo - ke tšobotsi e khethollang motho ka mong oa amino acid. Kahoo karolo ea cytoplasm ke efe ka protheine biosynthesis?

AK e hlaha ka likarolo tse kang li-ions, tse leng limolek'hule tse ts'oanang kapa tsa ho nka li-protone tsa hydrogen. Kahoo, sehlopha sa amino sa amino acid se fetoloa ho NH3 +, 'me sehlopha sa carbonyl se fetoloa ho COO-.

Ka kakaretso, AK AK e fumaneha ka tlhaho, e leng tse 20 feela tse etsoang li tšoeu. Har'a bona, ho na le sehlopha sa li-amino acid tse sa hlokahaleng 'meleng oa motho le ho kena seleng feela ka lijo tse amohelehang, le li-amino acid tse sa hlokahaleng tseo' mele o li bōpang.

Li-AK tsohle li koahetsoe ke codon e lumellanang le li-nucleotide tse tharo tsa mRNA, 'me e le' ngoe ea amino e ka 'na ea kenngoa ka likarolo tse' maloa tse joalo. Monyane oa methionine ka pro le eukaryotes ke ntlha ea pele, Mofuta oa phetoho o teng oa ketane ea peptide o qala. Li-codons tse emang li kenyelletsa sekhetho sa UAA, UGA le UAH.

Li-ribosomes ke eng?

Li-ribosomes li ikarabella joang bakeng sa likokoana-hloko tsa liprotheine tse seleng 'me karolo ea mehaho ee ke efe? Ntlha ea pele, tsena ke li-membrane, tse nang le likaroloana tse peli: tse kholo le tse nyane. Mosebetsi oa li-subunits tsena ke ho boloka molek'hule ea mRNA pakeng tsa bona.

Li-ribosomes ho na le libaka tseo mRNA e bitsoang codons e oelang ho eona. Ka kakaretso, pakeng tsa lihlopha tse nyenyane le tse khōlō, tse tharo tse joalo li ka lumellana.

Li-ribosomes tse 'maloa li ka kopanngoa ka mokhoa o le mong oa polysome e kholo, ka lebaka la hore na tekanyo ea ho qaptjoa ha ketane ea peptide e eketseha hakae,' me ha e tsoa, likopi tse 'maloa tsa protheine li ka fumanoa hang-hang. Ena ke karolo ea cytoplasm ka protheine biosynthesis.

Mefuta ea RNA

Ribonucleic acids e phetha karolo ea bohlokoa likarolong tsohle tsa ho ngolisoa. Ho na le lihlopha tse tharo tse kholo tsa RNA: lipalangoang, ribosomal le tlhahisoleseding.

MRNA e kenya letsoho ho fetisetsa boitsebiso bo mabapi le ho hlophisoa ha ketane ea peptide. TRNAs ke li-intermediates ho fetisetsa li-amino acid ho li-ribosomes, tse finyelloang ka ho thehoa ha metsoako ea aminoacyl-tRNA. Ho tlatswa ha amino acid e hlaha feela ka ho kopanngoa ho tlatsanang ha RNA ea likoloi tsa anticodon le codon ho RNA ea tlhahisoleseding.

RRNA e kenya letsoho ho thehoa ha ribosomes. Liphello tsa bona ke e 'ngoe ea mabaka a etsang hore mRNA e bolokehe pakeng tsa lihlopha tse nyane le tse khōlō. Li-Ribosomal RNA li thehoa nucleoli.

Bohlokoa ba liprotheine

Bothata ba likokoana-hloko tsa liprotheine le bohlokoa ba eona bakeng sa sele ke bo boholo: boholo ba limela tsa 'mele ke tsa mofuta oa peptide, ka lebaka la liprotheine, lintho li tsamaisoa ka lisele tsa sele.

Liprotheine li etsa mosebetsi oa motheo ha e le karolo ea mesifa, methapo le lisele tse ling. Karolo ea lipontšo ke ho fetisetsa boitsebiso bo mabapi le lits'ebetso tse etsahalang, ka mohlala, ha khanya e oela retina ea leihlo. Liprotheine tse sireletsang - immunoglobulins - ke motheo oa tsamaiso ea 'mele oa motho.