Hom proteins, lawv cov haujlwm thiab cov qauv

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2024-01-02 17:48

Raws li txoj kev xav ntawm Oparin-Haldane, lub neej hauv peb lub ntiaj teb yog los ntawm cov tee dej coacervate. Nws kuj yog ib qho protein molecule. Qhov ntawd yog, qhov kev txiav txim siab ua raws li nws yog cov tshuaj lom neeg uas yog lub hauv paus ntawm txhua lub neej uas muaj nyob niaj hnub no. Tab sis dab tsi yog cov qauv protein? Lawv ua lub luag haujlwm dab tsi hauv lub cev thiab tib neeg lub neej niaj hnub no? Cov proteins twg muaj? Wb sim saib seb.

Proteins: lub tswvyim dav dav

Los ntawm qhov pom ntawm cov qauv tshuaj, cov molecule ntawm cov khoom nyob rau hauv nqe lus nug yog ib theem ntawm cov amino acids interconnected los ntawm peptide bonds.

Txhua cov amino acid muaj ob pawg ua haujlwm:

• carboxylic -COOH;
• amino group -NH_2.

Nws yog nyob nruab nrab ntawm lawv uas ib daim ntawv cog lus tsim nyob rau hauv txawv molecules. Yog li, daim ntawv cog lus peptide muaj daim ntawv -CO-NH. Ib qho protein molecule yuav muaj ntau pua lossis ntau txhiab pab pawg, nws yuav nyob ntawm cov khoom tshwj xeeb. Cov hom ntawm cov proteins muaj ntau haiv neeg. Ntawm lawv muaj cov uas muaj cov amino acids tseem ceeb rau lub cev, uas txhais tau tias lawv yuav tsum tau noj nrog zaub mov. Muaj ntau yam ua haujlwm tseem ceeb hauv cov cell membrane thiabnws cytoplasm. Biological catalysts kuj raug cais - enzymes, uas kuj yog cov protein molecules. Lawv tau siv dav hauv tib neeg lub neej, thiab tsis tsuas yog koom nrog cov txheej txheem biochemical ntawm cov tsiaj nyob.

Qhov hnyav molecular ntawm cov tebchaw raws li kev txiav txim siab tuaj yeem nyob ntawm ntau kaum mus txog lab. Tom qab tag nrho, tus naj npawb ntawm monomer units nyob rau hauv ib tug loj polypeptide saw yog unlimited thiab nyob ntawm seb hom ntawm ib yam khoom. Protein nyob rau hauv nws daim ntawv ntshiab, nyob rau hauv nws haiv neeg conformation, yuav pom tau thaum kuaj ib tug nqaij qaib qe. Lub teeb daj, pob tshab, ntom colloidal loj, nyob rau hauv uas lub yolk nyob - qhov no yog cov khoom xav tau. Tib yam tuaj yeem hais tau rau cov tsev cheese uas tsis muaj rog, Cov khoom no tseem yuav luag cov protein ntshiab hauv nws daim ntawv ntuj.

Txawm li cas los xij, tsis yog txhua qhov sib xyaw ua ke nyob rau hauv kev txiav txim siab muaj cov qauv spatial tib yam. Nyob rau hauv tag nrho, plaub lub koom haum ntawm lub molecule yog txawv. Cov qauv ntawm cov protein txiav txim siab nws cov khoom thiab qhia txog qhov nyuaj ntawm cov qauv. Nws kuj tseem paub tias cov molecules spatially entangled ntau dhau los ua ntau yam hauv tib neeg thiab tsiaj.

Nyob ntawm cov qauv protein

Muaj plaub ntawm lawv tag nrho. Xav txog qhov lawv txhua tus yog dab tsi.

1. Pib. Sawv cev cov kab ke ib txwm muaj ntawm cov amino acids txuas nrog peptide bonds. Tsis muaj spatial twists, tsis muaj spiralization. Tus naj npawb ntawm cov kev sib txuas nrog hauv polypeptide tuaj yeem ncav cuag ntau txhiab. Hom proteins nrogCov qauv zoo sib xws - glycylalanine, insulin, histones, elastin thiab lwm yam.
2. Secondary. Nws muaj ob lub polypeptide chains uas yog twisted nyob rau hauv daim ntawv ntawm ib tug kauv thiab oriented ntawm ib leeg los ntawm tsim lem. Hauv qhov no, hydrogen bonds tsim ntawm lawv, tuav lawv ua ke. Qhov no yog li cas ib qho protein molecule raug tsim. Cov proteins ntawm hom no yog raws li nram no: lysozyme, pepsin thiab lwm yam.
3. Tertiary conformation. Nws yog ib qho densely packed thiab compactly coiled theem nrab qauv. Ntawm no, lwm yam kev sib cuam tshuam tshwm sim, ntxiv rau hydrogen bonds - qhov no yog van der Waals kev sib cuam tshuam thiab lub zog ntawm electrostatic attraction, hydrophilic-hydrophobic hu. Piv txwv ntawm cov qauv yog albumin, fibroin, silk protein thiab lwm yam.
4. Quaternary. Cov txheej txheem nyuaj tshaj plaws, uas yog ob peb polypeptide chains twisted rau hauv ib lub kauv, dov rau hauv ib lub pob thiab sib sau ua ke rau hauv ib lub globule. Piv txwv xws li insulin, ferritin, hemoglobin, collagen qhia txog qhov sib txawv ntawm cov protein.

Yog tias peb xav txog tag nrho cov qauv ntawm cov molecules hauv kev nthuav dav los ntawm kev pom tshuaj, ces kev tshuaj xyuas yuav siv sijhawm ntev. Qhov tseeb, qhov tseeb, qhov siab dua qhov kev teeb tsa, qhov nyuaj thiab qhov sib txawv ntawm nws cov qauv, ntau hom kev sib cuam tshuam tau pom nyob rau hauv molecule.

YDenaturation ntawm protein molecules

Ib qho ntawm cov tshuaj tseem ceeb tshaj plaws ntawm polypeptides yog lawv lub peev xwm ua kom tawg raws li kev cuam tshuam ntawm qee yam xwm txheej lossis tshuaj lom neeg. Yog li ntawd,Piv txwv li, ntau hom protein denaturation yog dav. Cov txheej txheem no yog dab tsi? Nws muaj nyob rau hauv kev puas tsuaj ntawm haiv neeg qauv ntawm cov protein. Ntawd yog, yog tias thaum xub thawj lub molecule muaj ib tug tertiary qauv, tom qab qhov kev txiav txim ntawm tshwj xeeb cov neeg ua hauj nws yuav vau. Txawm li cas los xij, cov kab ke ntawm cov amino acid residues tseem tsis hloov pauv hauv cov molecule. Denatured proteins sai sai poob lawv lub cev thiab tshuaj lom neeg lub zog.

Cov tshuaj reagents twg tuaj yeem ua rau cov txheej txheem ntawm kev puas tsuaj? Muaj ob peb tug.

1. Kub. Thaum rhuab, muaj kev puas tsuaj zuj zus ntawm quaternary, tertiary, theem nrab ntawm cov molecule. Visually, qhov no tuaj yeem pom, piv txwv li, thaum kib ib lub qe zoo tib yam. Qhov tshwm sim "protein" yog thawj cov qauv ntawm albumin polypeptide uas nyob hauv cov khoom nyoos.
2. Radiation.
3. Ua nrog cov tshuaj muaj zog: acids, alkalis, ntsev ntawm cov hlau hnyav, cov kuab tshuaj (piv txwv li, cawv, ethers, benzene thiab lwm yam).

txheej txheem no qee zaum kuj hu ua molecular melting. Cov hom protein denaturation nyob ntawm tus neeg sawv cev raws li qhov nws tau tshwm sim. Ntxiv mus, nyob rau qee kis, cov txheej txheem rov qab tshwm sim. Qhov no yog renaturation. Tsis yog tag nrho cov proteins tuaj yeem kho lawv cov qauv rov qab, tab sis ib feem tseem ceeb ntawm lawv tuaj yeem ua qhov no. Yog li, chemists los ntawm Australia thiab Amelikas tau ua qhov kev hloov pauv ntawm lub qe qaib qe uas siv qee cov tshuaj reagents thiab txoj kev centrifugation.

txheej txheem no tseem ceeb rau cov kab mob muaj sia nyob hauv kev sib txuas ntawm polypeptidechains ntawm ribosomes thiab rRNA hauv hlwb.

YHydrolysis ntawm cov protein molecule

Nrog rau kev ua kom zoo, cov proteins yog cov yam ntxwv ntawm lwm yam khoom siv tshuaj - hydrolysis. Qhov no kuj yog kev puas tsuaj ntawm haiv neeg conformation, tab sis tsis mus rau lub hauv paus qauv, tab sis tag nrho rau ib tug neeg amino acids. Ib qho tseem ceeb ntawm kev zom zaub mov yog protein hydrolysis. Cov hom hydrolysis ntawm polypeptides yog raws li nram no.

1. tshuaj. Raws li kev ua ntawm cov kua qaub lossis alkalis.
2. Zoo los yog enzymatic.

Txawm li cas los xij, qhov tseem ceeb ntawm cov txheej txheem tseem tsis hloov pauv thiab tsis nyob ntawm seb hom protein hydrolysis tshwm sim li cas. Yog li ntawd, cov amino acids yog tsim, uas yog thauj mus rau tag nrho cov hlwb, lub cev thiab cov ntaub so ntswg. Lawv qhov kev hloov pauv ntxiv muaj nyob rau hauv kev koom tes ntawm cov synthesis ntawm polypeptides tshiab, twb yog cov uas tsim nyog rau ib yam kab mob.

Hauv kev lag luam, cov txheej txheem ntawm hydrolysis ntawm cov protein molecules yog siv kom tau txais cov amino acids zoo.

Kev ua haujlwm ntawm cov protein hauv lub cev

Ntau hom proteins, carbohydrates, rog yog cov khoom tseem ceeb rau kev ua haujlwm ib txwm ntawm tes. Thiab qhov ntawd txhais tau hais tias lub cev tag nrho. Yog li ntawd, lawv lub luag haujlwm feem ntau yog vim qhov siab ntawm qhov tseem ceeb thiab qhov chaw nyob hauv cov tsiaj. Ob peb lub luag haujlwm tseem ceeb ntawm polypeptide molecules tuaj yeem paub qhov txawv.

1. Catalytic. Nws yog ua los ntawm cov enzymes uas muaj cov qauv protein. Peb yuav tham txog lawv tom qab.
2. Structural. Hom proteins thiab lawvkev ua haujlwm hauv lub cev feem ntau cuam tshuam rau cov qauv ntawm tes nws tus kheej, nws cov duab. Tsis tas li ntawd, polypeptides uas ua lub luag haujlwm no tsim cov plaub hau, rau tes, mollusc shells, thiab noog plaub. Lawv kuj yog ib yam armature nyob rau hauv lub cev ntawm lub cell. Pob txha mos kuj yog tsim los ntawm cov hom proteins no. Piv txwv li: tubulin, keratin, actin thiab lwm yam.
3. Regulatory. Qhov kev ua haujlwm no tau tshwm sim hauv kev koom tes ntawm polypeptides hauv cov txheej txheem xws li: kev sau ntawv, txhais lus, lub voj voog ntawm tes, splicing, mRNA nyeem ntawv, thiab lwm yam. Nyob rau hauv tag nrho cov ntawm lawv, lawv ua lub luag hauj lwm tseem ceeb ua tus tswj tsheb.
4. Signal. Qhov kev ua haujlwm no yog ua los ntawm cov proteins nyob rau ntawm lub cell membrane. Lawv xa cov cim sib txawv ntawm ib chav mus rau lwm qhov, thiab qhov no ua rau kev sib txuas lus ntawm cov ntaub so ntswg. Piv txwv li: cytokines, insulin, yam loj hlob thiab lwm yam.
5. Tsheb thauj mus los. Qee hom proteins thiab lawv cov haujlwm uas lawv ua tau tsuas yog qhov tseem ceeb. Qhov no tshwm sim, piv txwv li, nrog cov protein hemoglobin. Nws thauj oxygen los ntawm cell mus rau cell hauv cov ntshav. Rau ib tug neeg, nws yog irreplaceable.
6. Sparre or backup. Xws li polypeptides sau nyob rau hauv cov nroj tsuag thiab tsiaj qe ua ib qhov chaw ntawm kev noj haus ntxiv thiab lub zog. Ib qho piv txwv yog globulins.
7. Motiv. Ib qho haujlwm tseem ceeb heev, tshwj xeeb tshaj yog rau cov kab mob yooj yim tshaj plaws thiab cov kab mob. Tom qab tag nrho, lawv muaj peev xwm txav tau tsuas yog nrog kev pab ntawm flagella lossis cilia. Thiab cov organelles, los ntawm lawv cov xwm, tsis muaj dab tsi ntau tshaj li cov proteins. Piv txwv ntawm xws li polypeptides yog raws li nram no: myosin, actin, kinesin thiab lwm yam.

Nws pom tseeb tias kev ua haujlwm ntawm cov protein hauv tib neeg lub cev thiab lwm yamcov tsiaj muaj sia muaj ntau heev thiab tseem ceeb heev. Qhov no ib zaug ntxiv tau lees paub tias lub neej hauv peb lub ntiaj teb yog ua tsis tau yam tsis muaj qhov sib txuas uas peb xav txog.

tiv thaiv kev ua haujlwm ntawm cov protein

Polypeptides tuaj yeem tiv thaiv ntau yam cuam tshuam: tshuaj lom neeg, lub cev, lom. Piv txwv li, yog tias lub cev muaj kev phom sij nyob rau hauv daim ntawv ntawm tus kab mob los yog kab mob ntawm cov neeg txawv teb chaws, ces immunoglobulins (antibodies) nkag mus rau hauv kev sib ntaus sib tua nrog lawv, ua lub luag hauj lwm tiv thaiv.

Yog tias peb tham txog cov teebmeem ntawm lub cev, ces fibrin thiab fibrinogen, uas koom nrog hauv cov ntshav txhaws, ua lub luag haujlwm tseem ceeb ntawm no.

YNtaus proteins

Cov khoom noj muaj protein ntau yog raws li hauv qab no:

• ua tiav - cov uas muaj tag nrho cov amino acids tsim nyog rau lub cev;
• tsis tiav - cov uas muaj cov amino acid tsis tiav.

Txawm li cas los xij, ob qho tib si tseem ceeb rau tib neeg lub cev. Tshwj xeeb tshaj yog thawj pab pawg. Txhua tus neeg, tshwj xeeb tshaj yog thaum lub sijhawm muaj kev loj hlob hnyav (thaum me nyuam yaus thiab cov hluas) thiab cov laus, yuav tsum tswj hwm cov qib protein nyob hauv nws tus kheej. Tom qab tag nrho, peb twb tau txiav txim siab txog lub luag haujlwm uas cov molecules zoo kawg nkaus ua, thiab peb paub tias kev xyaum tsis yog tib txoj kev, tsis yog ib qho tshuaj biochemical hauv peb tuaj yeem ua yam tsis muaj kev koom tes ntawm polypeptides.

Yog vim li cas koj thiaj li yuav tsum tau noj cov protein kom tsawg txhua hnub, uas muaj nyob hauv cov khoom hauv qab no:

• egg;
• miv;
• tsev cheese;
• nqaij thiab ntses;
• taum;
• soy;
• taum;
• txiv laum huab xeeb;
• nqaij;
• oats;
• lentils thiab lwm yam.

Yog tias koj haus 0.6 g ntawm polypeptide ib kg ntawm qhov hnyav hauv ib hnub, ces tus neeg yuav tsis muaj cov tshuaj no. Yog hais tias ntev lub cev tsis tau txais cov protein tsim nyog, ces ib tug kab mob tshwm sim, uas muaj lub npe ntawm amino acid starvation. Qhov no ua rau muaj teeb meem loj hauv metabolic thiab, vim li ntawd, ntau lwm yam mob.

Proteins hauv lub tawb

Inside lub tsev me me tshaj plaws ntawm txhua yam nyob - hlwb - kuj muaj cov proteins. Ntxiv mus, lawv ua yuav luag tag nrho cov haujlwm saum toj no muaj. Ua ntej ntawm tag nrho cov, lub cytoskeleton ntawm lub cell yog tsim, muaj xws li microtubules, microfilaments. Nws pab tswj cov duab, nrog rau kev thauj mus los hauv nruab nrab ntawm cov organelles. Ntau yam ions thiab cov tebchaw txav mus raws cov protein molecules, xws li raws txoj kab lossis kev sib tw.

Lub luag haujlwm ntawm cov proteins rau hauv daim nyias nyias thiab nyob ntawm nws qhov chaw kuj tseem ceeb. Ntawm no lawv ua ob qho tib si receptor thiab teeb liab ua haujlwm, koom nrog kev tsim kho ntawm daim nyias nyias. Lawv sawv ntsug, uas txhais tau hais tias lawv ua lub luag haujlwm tiv thaiv. Dab tsi ntawm cov proteins hauv cell tuaj yeem raug ntaus nqi rau pawg no? Muaj ntau yam piv txwv, ntawm no yog ob peb.

1. Actin and myosin.
2. Elastin.

Keratin Keratin

3. YCollagen.
4. Tubulin.
5. YHemoglobin.

Insulin

6. YTranscobalamin.
7. Transferrin.
8. Albumin.

Muaj ntau puantau hom proteins uas niaj hnub txav mus los hauv txhua lub cell.

Cov proteins hauv lub cev

Lawv, tau kawg, ntau yam loj. Yog tias koj sim faib tag nrho cov proteins uas twb muaj lawm rau hauv pawg, koj tuaj yeem tau txais qee yam xws li kev faib tawm no.

1. Cov proteins thoob ntiaj teb. Cov no yog cov uas sawv cev los ntawm ib tug tertiary qauv, uas yog, ib tug ntom ntim globule. Piv txwv ntawm cov qauv no yog cov hauv qab no: immunoglobulins, feem ntau ntawm cov enzymes, ntau cov tshuaj hormones.
2. Fibrillar proteins. Lawv nruj nreem txiav threads nrog qhov tseeb spatial symmetry. Cov pab pawg no suav nrog cov proteins nrog cov qauv thawj thiab theem nrab. Piv txwv li, keratin, collagen, tropomyosin, fibrinogen.

Feem ntau, ntau yam tuaj yeem coj los ua lub hauv paus rau kev faib cov proteins hauv lub cev. Tseem tsis tau muaj tus.

YEnzymes

Cov tshuaj lom neeg lom neeg ntawm cov protein ntau, uas ua kom nrawm tag nrho cov txheej txheem biochemical txuas ntxiv mus. Ib txwm metabolism yog yooj yim tsis yooj yim sua yam tsis muaj cov tebchaw. Tag nrho cov txheej txheem ntawm synthesis thiab lwj, sib sau ua ke ntawm molecules thiab lawv replication, translation thiab transcription, thiab lwm yam yog nqa tawm nyob rau hauv lub cuam tshuam ntawm ib tug tshwj xeeb enzyme. Piv txwv ntawm cov molecules yog:

• oxidoreductase;
• transferases;
• catalase;
• Yhydrolases;
• isomerase;
• lyases and others.

Hnub no, enzymes tau siv hauv lub neej txhua hnub. Yog li, nyob rau hauv kev tsim cov ntxhua khaub ncawsHmoov feem ntau siv cov enzymes - cov no yog cov khoom siv roj ntsha. Lawv txhim kho qhov zoo ntawm kev ntxhua khaub ncaws thaum saib xyuas cov txheej txheem ntsuas kub. Yooj yim khi rau cov khoom siv av thiab tshem tawm ntawm qhov chaw ntawm cov ntaub.

Txawm li cas los xij, vim lawv qhov xwm txheej protein, enzymes tsis zam cov dej kub dhau los lossis qhov sib thooj rau cov tshuaj alkaline lossis acidic. Tseeb, nyob rau hauv cov ntaub ntawv no, tus txheej txheem ntawm denaturation yuav tshwm sim.