Protein biosynthesis - raws li nws tshwm sim?

Protein biosynthesis tshwm sim nyob rau hauv tag nrho cov kabmob, ntaub so ntswg thiab hlwb. Qhov loj tshaj plaws nqi ntawm cov protein tsim nyob rau hauv lub siab. Ribosomes nqa protein biosynthesis. Sib, ribosomes - nucleoproteins muaj li ntawm RNA (50-65%) thiab protein (35-50%). Ribonucleic acid yog Cheebtsam ntawm granular endoplasmic reticulum, qhov twg lub zog tshwm sim biosynthesis thiab tsim protein molecules.

Ribosomes muaj nyob hauv lub cell nyob rau hauv daim ntawv ntawm cov pawg ntawm 3 mus rau 100 units - polysomes (polyribosomes). Ribosomes feem ntau yog sib thooj, peculiar xov pom nyob rau hauv lub electron tshuab kuaj kab mob - thiab RNA.

Txhua ribosome Odin coj los ua ke lawv tus kheej polypeptide saw, ib tug pab pawg neeg - ob peb xws chains thiab protein molecules.

Cov kauj ruam uas muaj protein ntau biosynthesis

Ua kom cov amino acids. Nyob rau hauv hyaloplasm los ntawm interstitial kua raws li ib tug tshwm sim ntawm diffusion, osmosis los yog active thauj ntawm cov amino acids tau txais. Txhua yam ntawm cov amino thiab imino enzyme ua num ua ke nrog tus tib neeg - aminoatsilsintetazoy. Tshua tshuab txais magnesium cations, manganese, cobalt. Muaj tshuab txais amino acid.

Protein biosynthesis (thib ob theem) - thiab reacting lub compound nrog ib tug tshuab txais amino acid m-RNA. Tshuab txais amino acids (aminoacyl adenylate) siv enzymes pauv mus rau lub t-RNA ntawm lub cytoplasm. Cov txheej txheem yog tshwmsim los ntawm aminoacyl-tRNA synthetases. amino acid residue yog coupled rau ib tug hydroxyl pab pawg neeg ntawm cov carboxyl thib ob atom Carbo ribose nucleotide tRNA.

Protein biosynthesis (thib peb theem) - kev thauj mus los ntawm lub complex ntawm tshuab txais amino acid nrog m-RNA nyob rau hauv lub hlwb ntawm lub ribosome. Cov amino acid txuas mus rau lub tRNA, yog kis los ntawm hyaloplasm rau lub ribosome. Cov txheej txheem yog tshwmsim los ntawm kev enzymes, nyob rau hauv uas lub cev tsis yog tsawg tshaj li 20. Ib txhia amino acids yog thauj ob peb tRNA (e.g., valine thiab leucine - peb tRNA). Qhov no txoj kev siv lub zog ntawm GTP thiab ATP. Qhov thib plaub kauj ruam ntawm lub biosynthesis yog yus muaj los ntawm thwj toob ntawm aminoacyl-t-RNA complex thiab cov RNA - ribosome. Aminoacyl-tRNA, yuav mus rau qhov ribosome ua num ua ke nrog lub m-RNA. Txhua t-RNA feem yog muaj peb nucleotides - anticodon. Lub mRNA zajlus nws sau raws nkaus Ii peb nucleotides - codon. Txhua codon sib tRNA anticodon thiab ib tug amino acid. Thaum lub sij hawm biosynthesis uas txuas mus rau lub ribosomes nyob rau hauv daim ntawv aminoacyl-tRNA amino acids, uas hereinafter nyob rau hauv qhov kev txiav txim txiav txim nyob rau hauv qhov kev tso kawm ntawm codons thiab mRNA yog tsim nyob rau hauv lub polypeptide saw.

Cov theem tom ntej ntawm protein synthesis - yog qhov pib ntawm lub polypeptide saw. Tom qab ob lub neighboring aminoacyl-tRNA anticodon koom rau lawv codon-RNA, lub tej yam kev mob rau lub synthesis ntawm ib tug polypeptide saw. Txoj kev ua ib peptide daim ntawv cog lus. Cov dab no yog tshwmsim peptide synthetases, tshuab txais Mg cations thiab protein xwm pib yam F1, F2, F3. Yog qhov uas cov tshuaj lub zog yog guanozintrifosfatnaya acid.

Txiav ntawm lub polypeptide saw. Lub ribosome, uas twb tsim rau ntawm qhov chaw ntawm lub polypeptide saw, thiab cov saw hlau nce mus txog qhov kawg-RNA, hereinafter "jumps" tawm ntawm nws. Yuav kom cov lus rov rau thaum xaus ntawm lub mRNA txuas nyob rau hauv nws qhov chaw ib tug tshiab ribosome, uas synthesizes lwm polypeptide molecules. Lub polypeptide saw yog tu los ntawm lub ribosome thiab yog tas nyob rau hauv hyaloplasm. Qhov no cov tshuaj tiv thaiv yog nqa tawm siv ib txog kev tso tawm tau (R), uas yog kev cob cog rua nrog lub ribosome thiab tswj lub hydrolysis ntawm lub ether linkage ntawm lub polypeptide thiab tRNA.

Ethers thiab tsim nyob rau hauv hyaloplasm polypeptide chains ntawm complex proteins. Tsim theem nrab, tertiary thiab nyob rau hauv ntau mob - lub quaternary qauv ntawm cov protein molecule. Yog li muaj protein biosynthesis nyob rau hauv lub cell.