Thaum lub sij hawm lub synthesis ntawm cov nqaijrog ncaj qha kev koom tes yog dab tsi lug thiab molecules?

Protein - nws yog vitally qho tseem ceeb rau tej kab mob tshuaj. Lawv muab kev koom tes nyob rau hauv tag nrho cov metabolic kev ntawm hlwb yog cov building blocks hauv nruab nrog cev thiab cov nqaij mos ua raws li taw molecules. Thaum lub sij hawm lub synthesis ntawm cov nqaijrog ncaj qha kev koom tes ntau enzymes, raws li zoo raws li cell organelles thiab ib tug keeb.

Cov kauj ruam uas muaj protein ntau synthesis: Lom Science News for KIDS

Mechanism ntawm protein molecules constructing heev tham thiab yuav tsum tau ib tug loj tus naj npawb ntawm yam. Peptides muaj li ntawm ob peb molecules ntawm amino acids, thiab lawv muaj pes tsawg mas nws txawv nyob rau hauv ib tug heev ntau yam.

Kom cov lag luam nyob rau cov protein ntau conformation ntawm lub molecule, thiab tus naj npawb ntawm cov amino acids thiab lawv muaj tseeb ua ntu zus nyob rau hauv lub peptide. Ntaub ntawv hais txog qhov no yog muab cia rau hauv lub DNA theem zuj zus, thiab nws ntxaug vim change thiab lwm yam yuav ua tau kom shutdown ntawm tseem ceeb heev cov nqaijrog thiab cell tuag.

Faib raws li nram no cov kauj ruam ntawm protein synthesis nyob rau hauv lub cell :

1. transcription.

2. Tshaj tawm hauv xov.

Kauj ruam ib: transcription

Thaum lub sij hawm lub synthesis ntawm cov nqaijrog ncaj qha kev koom tes nucleic acid molecules. DNA li cov repository ntawm tag nrho cov kev tshuaj ntsuam genetic ntaub ntawv yog kho siv nws yam ntxwv nucleotide ib theem zuj zus ntawm lub peptide ntawm lub neej yav tom ntej. Pib nrog lub caij pib codon (triplet) mus rau lub davhlau ya nyob twg, cov ntaub ntawv no nyeem protein mus rau lwm nucleic acid - RNA. Qhov no ib saw molecule yog kis los ntawm pores nyob rau hauv lub cell nucleus nyob rau hauv lub cytoplasm.

Yog hais tias eukaryotic transcription txheej txheem yog fraught nrog nucleus, prokaryotes nws tsis tuaj kawm ntawv simplifies peptide synthesis. RNA, uas yog tsim nyob rau tus kab mob chromosome, ces yog ua thiab yog txuas mus rau lub ribosomes.

Enzymes ua si ib qho tseem ceeb heev luag hauj lwm nyob rau hauv cov tsim thiab cov synthesis ntawm RNA rau ib tug DNA template. Nyob rau hauv tus txheej txheem ntawm cov protein synthesis ncaj qha kev koom tes molecules xws li transcription yam, los yog TF. Qhov no yog ib tug series ntawm cov nqaijrog uas txhawb cov ndlwg ntawm tus txheej txheem ntawm kev nyeem ntawv ntaub ntawv los ntawm lub deoxyribonucleic acid.

Kauj ruam ob: Tshaj tawm hauv xov

Thaum RNA nkag mus rau hauv cytoplasm ntawm lub cell los ntawm cov tub ntxhais, cov ntaub ntawv nyob rau hauv nyob tus yeees ntawm cov peptide yuav tsum tau nyeem los yog tshwj xeeb lug. Thaum lub sij hawm lub synthesis ntawm cov nqaijrog ncaj qha kev koom tes ribosomes - uas tsis yog-daim nyias nyias, me kab uas hla lug li ntawm ob subunits: loj thiab me me. RNA muab tso rau nruab nrab ntawm cov ob subunits, thiab ces pib nyeem cov ntaub ntawv.

Codon yog ib tug codon rau lub build ntev protein molecules ntawm rab phom hom. Qhov no yog piav raws li nram no: nyob rau hauv lub qhov chaw ntawm mezhribosomalnom muab tso tsuas yog ob tug codon tam sim ntawd. Thaum ib tug ntawm lawv twb tau nyeem, cov amino acid yog txuas mus rau lub peptide, thiab ntog los ntawm cov ribosome los ntawm ib tug tshwj xeeb qhov nyob rau hauv daim ntawv ntawm ib hom tus Tsov tus tw. Qhov no tshwm sim raws li lub tes tsho dauv los ntawm rab phom tom qab firing.

Thaum lub sij hawm lub synthesis ntawm cov nqaijrog ncaj qha kev koom tes pab pawg YOG cov nqaijrog, los yog pib yam. Nrog lawv pab, polypeptide synthesis pib nrog ib tug pib codon, uas nyob rau hauv feem ntau yog methionine.

Nws yog ib nqi hais tias cov amino acids yog xa mus rau lub ribosomes los ntawm tshwj xeeb muaj hu ua tRNA los yog hloov mus rau lwm RNA. Cov molecules muaj tus duab ntawm ib tug cloverleaf, thiab nyob rau thaum xaus ntawm uas koom lub amino acid, raws li zoo raws li ATP thiab tshwj xeeb protein - aminoacyl-tRNA synthetase. Tag nrho cov no complex ua ke enables ib tug zog expenditure tivthaiv xa ntxwv protein mus rau lub ribosome thiab muab ntawm ib tug peptide daim ntawv cog lus.

Yuav ua li cas yog nucleotides?

Nucleic acid - ib pab pawg neeg ntawm cov organic tebchaw uas yog polymers. Lawv muaj xws li ib tug purine (adenine, guanine) thiab pyrimidine (thymine, cytosine, uracil) bases. Cov kab sab ntawm cov nucleotides thiab txiav txim seb cov ntaub ntawv khaws tseg nyob rau hauv lub DNA los yog RNA. Cov lus no yog nyeem nyob rau hauv lub ribosomes yuav tsim cov nqaijrog, thiab rau yooj yim ntawm kev siv kev pab raws qib no lawm cia rau hauv nucleotide triplets. Txhua triplet encodes nws amino acids, uas yuav muab kev pab tRNA mus rau lub ribosome.

Synthesis of mitochondrial cov nqaijrog

Mitochondria thiab plastids muaj yus feature - lawv muaj lawv tus kheej yeej DNA, xws kab mob chromosome ntawm cov kab mob. Nrog rau qhov no organelle nucleic acid yuav khiav lag luam autonomously ua ke lawv feem ntau cov yam ntxwv proteins.

Txawm li cas los, mitochondrial DNA yog tsis khaws cia ntaub ntawv zoo tshaj cov nqaijrog uas tsim nyog rau tus txheej txheem ntawm transcription thiab txhais lus. Cov peptides tau koom ua ke rau ribosomes siv RNA tsis mitochondria thiab lub nucleus. Yog li ntawd dvumembrannye lug tsis tag ywj siab.

Yuav ua li cas mitochondria thiab plastids tau pom lawv tus kheej DNA? Nws yog assumed tias cov organelles yog xeeb leej xeeb ntxwv ntawm cov kab mob. Lawv poob intracellularly kev ywj siab, txawm li cas los, coj nrog ib tug annular nucleic acid. Qhov no qhia zoo sib xws thiab mitochondrial DNA nrog ib tug zoo xws li cov molecule prokaryotes.

xaus

Tag nrho cov kauj ruam ntawm protein synthesis txuam nrog txhua lwm yam, thiab lawv ua hauj lwm yog los mus tsim ib tug peptide molecules siv ntaub ntawv khaws tseg nyob rau hauv nucleic acids. Qhov tam sim ntawd lam yog lug xws li cov nucleus thiab ribosomes, thiab kuj ib co tshwj xeeb proteins.

Nyob rau hauv prokaryotes, lub peptides synthesis txheej txheem yuav siv sij hawm qhov chaw sai npaum li cas vim lub fact tias lawv tsis muaj ib tug nucleus. RNA, uas yog transcribed nyob rau hauv lub matrix ntawm cov kab mob DNA, ces koom lub ribosomes, thiab ces ib txhij ntws kuj tshaj tawm hauv xov.