Yuav ua li cas yog protein? Piv txwv ntawm tej yam yooj yim thiab complex cov nqaijrog

Yuav kom to taub li cas tseem ceeb yog cov proteins, nws suffices nco qab lub zoo npe hu kab lus Fridriha Engelsa: "Lub neej - ib txoj kev ntawm hav zoov uas muaj protein ntau lub cev." Nyob rau hauv qhov tseeb, nyob rau hauv lub ntiaj teb no ntawm cov tshuaj nyob rau hauv tas li ntawd mus nucleic acids, ua tag nrho cov kev tshwm sim uas muaj sia nyob muaj teeb meem. Nyob rau hauv daim ntawv no, peb yuav nrhiav tau tawm yog dab tsi nws muaj protein, kawm tej yam ua nws ua raws li zoo raws li txhais tau lub yam ntxwv nta ntawm lub hom sib txawv.

Peptides - yeej npaj polymers

Tseeb, nyob rau hauv ib tug nyob ntawm tes raws li nroj tsuag thiab tsiaj nqaijrog quantitatively predominant tshaj lwm yam organic tshuaj, raws li zoo raws li koj khiav lag luam tus loj tshaj xov tooj ntawm txawv zog. Lawv koom nyob rau hauv ib tug ntau yam ntawm tseem ceeb heev cellular dab, xws li lub zog, kev tiv thaiv, tswb muaj nuj nqi thiab thiaj li nyob. Piv txwv li, nyob rau hauv tej nqaij ntawm cov tsiaj thiab tib neeg peptides comprise mus txog 85% los ntawm qhov hnyav ntawm qhuav teeb meem, thiab nyob rau hauv cov pob txha thiab dermis - los ntawm 15-50%.

Tag nrho cov cellular thiab cov nqaij mos proteins uas muaj li ntawm amino acids (20 hom). Lawv tus xov tooj nyob rau hauv uas muaj sia nyob yog yeej ib txwm sib npaug zos rau nees nkaum hom. Ntau yam ob peb ua ke ntawm peptide monomers tsim tau ib cov ntau yam ntawm cov nqaijrog nyob rau hauv cov xwm. Nws yog kwv yees li lub astronomical tooj ntawm 2x10 ¹⁸ tau hom. Nyob rau hauv biochemistry polypeptides hu ua macromolecular lom polymers - macromolecules.

Amino acids - protein monomers

Tag nrho 20 hom ntawm cov tshuaj tebchaw yog cov nqaijrog thiab structural units muaj cov kev mis NH ₂ -R-COOH. Lawv yog cov amphoteric organic tshuaj uas muaj peev xwm rau ib ce muaj zog ob yam basic thiab acidic zog. Tsis tsuas yog yooj yim cov nqaijrog, tab sis kuj complex, muaj thiaj li hu ua qhov tseem ceeb cov amino acids. Tab sis qhov tseem ceeb monomers, xws li valine, lysine, methionine yuav pom xwb nyob rau hauv tej yam hom belkov.Takie cov nqaijrog xa mus rau raws li high-qib.

Yog li ntawd, characterizing lub polymer rau hauv tus account tsis tau tsuas yog yuav ua li cas muaj ntau yam ntawm cov amino acids yog protein, tab sis kuj zoo li cas ntawm monomers yog koom los ntawm peptide bonds nyob rau hauv lub macromolecule. Ntxiv ntawd nonessential amino acids xws li asparagine, glutamic acid, cysteine tej zaum yuav nws tus kheej tsim nyob rau hauv lub hlwb ntawm tib neeg thiab tsiaj. Qhov tseem ceeb monomers yog cov nqaijrog ua nyob rau hauv cov kab mob, nroj tsuag thiab fungi. Lawv tuaj nyob rau hauv heterotrophic kab mob tsuas nrog cov zaub mov.

Raws li ua polypeptide

Raws li yog lub npe hu, 20 sib txawv amino acids yuav tsum ua ke rau ib tug plurality ntawm no yam uas muaj protein ntau molecules. Yuav ua li cas yog tus thwj toob ntawm monomers nrog txhua lwm yam? Nws zoo nkaus li uas lub carboxyl thiab amine pawg ntawm nyob ib sab amino acids dag sib tham. Ib tug thiaj li hu ua peptide bonds, thiab dej lwg me me yog faib raws li ib tug byproduct ntawm lub polycondensation cov tshuaj tiv thaiv. Cov uas ua protein molecule muaj amino acid residues thiab repetitive peptide bonds. Yog li ntawd lawv kuj hu ua polypeptides.

Feem ntau, cov nqaijrog yuav muaj tsis yog ib tug tab sis ob peb polypeptide chains thiab muaj ntau txhiab ntawm cov amino acid residues. Ntxiv mus, yooj yim cov nqaijrog thiab muaj peev xwm proteid complicate lawv spatial configuration. Qhov no ua ib qho kev tsis tau tsuas yog rau cov thawj, tab sis kuj theem nrab, tertiary thiab txawm quaternary qauv. Cia peb kawm tus txheej txheem no nyob rau hauv ntau yam. Ntxiv rau lo lus nug ntawm yog dab tsi tshwm sim tawm ib protein, nrhiav seb yog dab tsi lub configuration muaj no macromolecule. Peb tau pom tias ib tug polypeptide saw muaj ib tug plurality ntawm covalent tshuaj bonds. Nws yog ib qhov qauv no yog hu ua cov thawj.

Nws plays ib qho tseem ceeb luag hauj lwm hauv ntau thiab zoo muaj pes tsawg leeg ntawm amino acids, raws li zoo raws li lub ib theem zuj zus ntawm lawv kev twb kev txuas. Secondary qauv tshwm sim thaum lub caij ntawm lub helix. Nws stabilizes ntau tshiab khiv tawm hydrogen bonds.

Feem ntau ntawm cov protein lub koom haum

Tertiary qauv yog ib tug ntawm ntim kauv nyob rau hauv daim ntawv ntawm ib lub pob - globules, e.g., nqaij protein myoglobin ntaub muaj xws li ib tug spatial qauv. Nws yog txaus siab raws li tshiab khiv tsim los ntawm hydrogen bonds, thiab disulfide bonds (yog tias cysteine residues muaj xws li ob peb protein molecule). Quaternary daim ntawv - qhov no yog qhov tshwm sim ntawm combining rau hauv ib lub tsev ob peb protein globules los ntawm tshiab hom ntawm kev sib tshuam, xws li hydrophobic los yog electrostatic. Nrog rau lub peptides thiab quaternary qauv muaj xws li nonproteinaceous feem. Cov no tej zaum yuav magnesium ions, hlau, tooj liab los yog residues orthophosphate los yog nucleic acids, thiab lipids.

Nta protein biosynthesis

Peb tau yav tas los pom seb muaj dab tsi nws muaj protein. Nws yuav ua tau amino acid ib theem zuj zus. Lawv los ua ke rau hauv ib lub polypeptide saw yuav siv sij hawm qhov chaw nyob rau hauv lub ribosomes - uas tsis yog-daim nyias nyias organelles, nroj tsuag thiab tsiaj hlwb. Nyob rau hauv lub biosynthesis ntawm cov molecule kuj muab kev koom tes cov ntaub ntawv thiab hloov mus rau lwm RNA. Tus thawj yog ib tug qauv rau cov protein ntau los ua ke thiab lub thib ob conveying ntau yam amino acids. muaj yog ib lub teeb meem nyob rau hauv tus txheej txheem ntawm cellular biosynthesis, namely, protein muaj nucleotides los yog amino acids? Cov lus teb yog yooj yim - cov polypeptides ntawm ob yooj yim thiab complex muaj amphoteric organic tebchaw - amino acids. Nyob rau hauv lub neej voj voog ntawm lub hlwb , muaj lub sij hawm ntawm txoj kev thaum lub protein synthesis yuav siv sij hawm qhov chaw tshwj xeeb. Qhov no thiaj li hu ua theem J1 thiab J2 interphase. Thaum lub sij hawm no, lub cell yog koom loj hlob thiab xav tau ib tug ntau ntawm cov tsev ntaub, uas yog protein. Tsis tas li ntawd, raws li ib tug tshwm sim ntawm mitotic xaus daim ntawv ob tus ntxhais lub hlwb, txhua tus uas xav tau ib tug loj npaum li cas ntawm cov organic tshuaj, txawm li cas los nyob rau hauv lub raws tus endoplasmic reticulum yog active synthesis ntawm lipids thiab carbohydrates, thiab nyob rau hauv lub granular Epm tshwm sim biosynthesis ntawm proteins.

Lub zog ntawm cov nqaijrog

Paub txog dab tsi ua rau ib tug muaj protein ntau, nws yuav piav raws li ib tug lossis loj ntau yam ntawm hom, thiab cov khoom nws xam qhovkev nyob rau hauv cov tshuaj. Cov nqaijrog ua nyob rau hauv lub tawb ib tug ntau yam ntawm kev khiav dej num, xws li kev tsim kho, raws li ib feem ntawm cov daim nyias nyias ntawm tag nrho cov hlwb thiab organelles: mitochondria, chloroplasts, lysosomes, Golgi complex, thiab hais txog. Tej peptides li gamoglobuliny los yog antibody - yog cov piv txwv ntawm tej yam yooj yim proteins uas ua tau ib tug tiv thaiv muaj nuj nqi. Nyob rau hauv lwm yam lus, cellular tiv thaiv - qhov no yog qhov tshwm sim ntawm kev txiav txim ntawm cov tshuaj. Ib tug complex protein - yaum sij, nrog rau hemoglobin, nqa tawm tsiaj thauj muaj nuj nqi, uas yog, cov pa oxygen hauv cov ntshav. Taw cov nqaijrog uas ua tau lub cell daim nyias nyias, lub cell ntaub ntawv mus rau muab on tshuaj, ua kom tau nyob rau hauv nws cytoplasm. Albumin peptide yog lub luag hauj lwm rau qhov yooj yim tsis ntawm cov ntshav, piv txwv li, rau nws muaj peev xwm los khov rau ntawd. Protein ovalbumin Tshuag lub qe nyob rau hauv ib lub tawb, thiab qhov tseem ceeb ntawm cov as-ham.

Cov nqaijrog - lub hauv paus ntawm lub cell cytoskeleton

Ib tug ntawm cov tseem ceeb functions ntawm peptides - kev pab txhawb nqa. Nws yog ib qho tseem ceeb heev kom muaj lub zoo thiab ntim ntawm nyob hlwb. Lub thiaj li hu ua qauv submembrane - microtubules thiab microfilaments intertwined tsim ib tug nrog lub cev pob txha ntawm lub hlwb. Cov nqaijrog muaj nyob rau hauv lawv cov muaj pes tsawg leeg, e.g., tubulin, yuav nkag tau muab compressed thiab ncav us txog. Qhov no yuav pab kom cov cell kom muaj nws zoo nyob rau hauv cov neeg kho tshuab deformations.

Nyob rau hauv cog hlwb, nrog rau cov nqaijrog hyaloplasm, cov yuav txhawb muaj nuj nqi kuj khiav lag luam strands cytoplasm - plasmodesmata. Dhau los ntawm lub pores nyob rau hauv lub cell phab ntsa, lawv ua rau lub kev sib raug zoo ntawm ib tug xov tooj ntawm lwm cellular lug uas tsim cov nroj tsuag cov ntaub so ntswg.

Enzymes - ib yam khoom uas muaj protein ntau cov xwm

Ib tug ntawm cov tseem ceeb tshaj plaws thaj chaw ntawm cov nqaijrog - lawv ntxim rau cov nqi ntawm cov tshuaj tshua. Basic cov nqaijrog yog tau cov denature - unwinding txheej txheem macromolecule nyob rau hauv tertiary los yog quaternary qauv. Tus heev tib yam polypeptide saw tseem tsis tau tawg. Ib nrab denaturation underlies ob lub teeb liab thiab cov catalytic muaj nuj nqi ntawm cov protein. Cov yav tas cuab yeej yog cov muaj peev xwm ntawm enzymes los txhawb rau tus nqi ntawm biochemical kev tig cev nyob rau hauv lub nucleus thiab cytoplasm ntawm lub hlwb. Peptides uas, conversely, thiaj li tus nqi ntawm cov tshuaj dab tsis hu ua enzymes thiab inhibitors. Piv txwv li, ib tug yooj yim protein Catalase yog ib qho enzyme uas accelerates lub splitting ntawm hydrogen peroxide ntawm tej yam tshuaj lom. Nws yuav ua raws li qhov kawg khoom ntawm ntau tshuaj tshua. Catalase accelerates nws pov tseg rau nruab nrab tshuaj, dej thiab oxygen.

thaj chaw ntawm cov nqaijrog

Lub peptides yog txwv kom muab zais nyob rau hauv ntau txoj kev. Piv txwv li, nrog rau kev hwm rau cov dej muaj peev xwm yuav muab faib ua hydrophilic thiab hydrophobic. Kub kuj txawv cuam tshuam cov qauv thiab cov thaj chaw ntawm cov protein molecules. Piv txwv li, keratin protein - cov plaub hau thiab ntsia thawv tivthaiv yuav mas neb ob leeg tsawg tsawg thiab siab kub, i.e. yog thermolabile. Tab sis lub protein ovalbumin, hais ua ntej lawm, thaum rhuab mus 80-100 ° C yog tag pov tseg. Qhov no txhais tau tias nws yog phua rau hauv cov thawj cov qauv ntawm cov amino acid residues. Qhov no yog hu ua kev puas tsuaj. Txawm tej yam kev mob, peb tsis tau tsim, nyob rau hauv lub haiv neeg hauv daim ntawv ntawm cov protein rov qab tsis tau. Tsav protein - actin thiab milozin tam sim no nyob rau hauv cov nqaij fibers. Lawv lwm contraction thiab so yog lub hauv paus ntawm nqaij ua hauj lwm.