Raws li koj paub, cov proteins yog lub hauv paus rau lub hauv paus ntawm lub neej nyob rau hauv peb ntiaj chaw. Raws li Oparin-Haldane txoj kev xav, nws yog coacervate poob, muaj cov peptide molecules, uas tau los ua lub hauv paus rau kev yug los ntawm cov khoom muaj sia. Qhov no yog qhov tsis ntseeg, vim hais tias kev tsom xam ntawm cov khoom siv sab hauv ntawm ib tus neeg sawv cev ntawm biomass qhia tias cov tshuaj no muaj nyob hauv txhua yam: nroj tsuag, tsiaj txhu, kab mob, kab mob, fungi, kab mob. Ntxiv mus, lawv muaj ntau haiv neeg thiab macromolecular hauv xwm.
Cov qauv no muaj plaub lub npe, lawv yog tag nrho cov ntsiab lus:
- proteins;
- proteins;
- peptides.
Ypolypeptides;
Y
Protein molecules
Lawv tus lej yog suav tsis tau tiag. Ntxiv mus, tag nrho cov protein molecules tuaj yeem muab faib ua ob pawg loj:
- yooj yim - tsuas yog muaj cov amino acid sequences txuas los ntawm peptide bonds;
- nyuaj - cov qauv thiab cov qauv ntawm cov protein yog tus cwj pwm los ntawm cov pab pawg protolytic ntxiv (prosthetic), tseem hu ua cofactors.
Tib lub sijhawm, cov molecules complex kuj muaj lawv tus kheej kev faib tawm.
Kev sib tw ntawm cov peptides complex
- Glycoproteins yog cov sib txuas ntawm cov protein thiab carbohydrate. nyob rau hauv cov qauv ntawm cov moleculeProsthetic pawg ntawm mucopolysaccharides yog intertwined.
- Lipoproteins yog ib qho sib xyaw ntawm cov protein thiab lipid.
- Metalloproteins - hlau ions (hlau, manganese, tooj liab thiab lwm yam) ua raws li ib pab pawg neeg prosthetic.
- Nucleoproteins - kev sib txuas ntawm cov protein thiab nucleic acids (DNA, RNA).
- Phosphoproteins - kev sib haum xeeb ntawm cov protein thiab ib qho orthophosphoric acid residue.
- Chromoproteins - zoo ib yam li metalloproteins, txawm li cas los xij, lub caij uas yog ib feem ntawm cov pab pawg pob txha yog cov xim tag nrho (liab - hemoglobin, ntsuab - chlorophyll, thiab lwm yam).
Txhua pab pawg muaj cov qauv sib txawv thiab cov khoom ntawm cov protein. Cov haujlwm uas lawv ua kuj txawv nyob ntawm seb hom molecule.
Tshuaj cov qauv ntawm cov proteins
Los ntawm qhov kev pom no, cov proteins yog cov saw ntev ntev ntawm cov amino acid residues sib cuam tshuam los ntawm cov nyiaj tshwj xeeb hu ua peptide bonds. Los ntawm sab qauv ntawm cov kua qaub tawm ceg - radicals. Cov qauv ntawm cov molecule no tau pom los ntawm E. Fischer thaum pib ntawm lub xyoo pua 21st.
Tom qab, cov proteins, cov qauv thiab cov haujlwm ntawm cov proteins tau kawm kom ntxaws ntxiv. Nws tau pom tseeb tias tsuas muaj 20 amino acids uas tsim cov qauv ntawm peptide, tab sis lawv tuaj yeem ua ke rau ntau txoj hauv kev. Vim li no, kev sib txawv ntawm cov qauv polypeptide. Tsis tas li ntawd, nyob rau hauv cov txheej txheem ntawm lub neej thiab kev ua tau zoo ntawm lawv cov dej num, cov proteins muaj peev xwm mus dhau ib tug xov tooj ntawm cov tshuaj hloov pauv. Yog li ntawd, lawv hloov cov qauv, thiab ib qho tshiab kiag lihom kev sib txuas.
Txhawm rau rhuav tshem cov peptide daim ntawv cog lus, uas yog, txhawm rau txhawm rau cov protein, cov qauv ntawm cov saw hlau, koj yuav tsum xaiv cov xwm txheej hnyav (qhov kev txiav txim siab kub, acids lossis alkalis, catalyst). Qhov no yog vim lub zog siab ntawm covalent bonds hauv cov molecule, uas yog nyob rau hauv pawg peptide.
Kev kuaj xyuas cov qauv ntawm cov protein hauv chav kuaj yog ua los ntawm kev siv cov tshuaj tiv thaiv biuret - raug cov polypeptide rau freshly precipitated tooj liab (II) hydroxide. Lub complex ntawm peptide pab pawg neeg thiab cov tooj liab ion muab ib tug kaj liab doog xim.
Muaj plaub lub koom haum tseem ceeb, txhua tus muaj nws tus kheej cov yam ntxwv ntawm cov proteins.
Levels of Organisation: Primary Structure
Raws li tau hais los saum toj no, peptide yog ib ntu ntawm cov amino acid residues nrog lossis tsis suav nrog, coenzymes. Yog li lub npe tseem ceeb yog cov qauv ntawm cov molecule, uas yog ntuj, ntuj, yog cov amino acids tiag tiag txuas nrog peptide bonds, thiab tsis muaj dab tsi ntxiv. Ntawd yog, polypeptide ntawm cov qauv linear. Nyob rau tib lub sijhawm, cov yam ntxwv ntawm cov proteins ntawm cov phiaj xwm zoo li no yog qhov kev sib xyaw ua ke ntawm cov kua qaub yog qhov txiav txim siab rau kev ua haujlwm ntawm cov protein molecule. Vim tias muaj cov yam ntxwv no, nws muaj peev xwm tsis tsuas yog txheeb xyuas cov peptide, tab sis kuj los kwv yees cov khoom thiab lub luag haujlwm ntawm ib qho tshiab kiag li, tseem tsis tau pom. Piv txwv ntawm peptides nrog lub ntuj tsim qauv yog insulin, pepsin, chymotrypsin thiab lwm yam.
kev sib tw thib ob
Cov qauv thiab cov khoom ntawm cov proteins hauv pawg no hloov pauv me ntsis. Cov qauv zoo li no tuaj yeem tsim los ntawm qhov xwm txheej lossis thaum raug rau thawj zaug nyuaj hydrolysis, kub lossis lwm yam mob.
Qhov kev sib haum xeeb no muaj peb hom:
- Smooth, tsis tu ncua, stereoregular coils ua los ntawm cov amino acid residues uas twist nyob ib ncig ntawm lub ntsiab axis ntawm kev sib txuas. Lawv tuav ua ke tsuas yog los ntawm hydrogen bonds uas tshwm sim ntawm oxygen ntawm ib pawg peptide thiab hydrogen ntawm lwm tus. Ntxiv mus, cov qauv yog suav hais tias yog vim lub fact tias cov lem yog sib npaug zos rau txhua 4 txuas. Cov qauv zoo li no tuaj yeem yog sab laug lossis sab xis. Tab sis nyob rau hauv feem ntau paub cov proteins, lub dextrorotatory isomer predominates. Cov kev sib haum xeeb no hu ua alpha structures.
- Cov muaj pes tsawg leeg thiab cov qauv ntawm cov proteins ntawm hom hauv qab no txawv ntawm qhov dhau los hauv cov ntawv cog lus hydrogen yog tsim tsis yog ntawm cov seem uas nyob ib sab ntawm ib sab ntawm cov molecule, tab sis nruab nrab ntawm cov chaw deb heev, thiab ntawm qhov txaus. loj nyob deb. Vim li no, tag nrho cov qauv siv ntau lub wavy, serpentine polypeptide chains. Muaj ib qho tshwj xeeb uas cov protein yuav tsum tau nthuav tawm. Cov qauv ntawm cov amino acids ntawm cov ceg yuav tsum luv li sai tau, xws li glycine lossis alanine, piv txwv li. Hom kev hloov pauv thib ob no yog hu ua cov nplooj ntawv beta rau lawv lub peev xwm los ua ke los ua ib qho qauv.
- Biology hais txog peb hom protein ntau licomplex, tawg, disordered fragments uas tsis muaj stereoregularity thiab muaj peev xwm hloov cov qauv nyob rau hauv lub cuam tshuam ntawm sab nraud tej yam kev mob.
Tsis muaj cov piv txwv ntawm cov protein tshwm sim tau raug txheeb xyuas.
Tertiary education
Qhov no yog ib qho kev sib haum xeeb hu ua "globule". Cov protein no yog dab tsi? Nws cov qauv yog raws li cov qauv thib ob, tab sis cov kev sib tshuam tshiab ntawm cov atoms ntawm pawg tau ntxiv, thiab tag nrho cov molecule zoo li quav, yog li tsom rau qhov tseeb tias cov pab pawg hydrophilic tau qhia hauv lub globule, thiab pawg hydrophobic. raug coj mus rau sab nraud.
Qhov no piav qhia txog tus nqi ntawm cov protein molecule hauv cov tshuaj colloidal dej. Dab tsi ntawm kev sib cuam tshuam muaj?
- Hydrogen bonds - nyob twj ywm tsis hloov ntawm tib qhov chaw ib yam li hauv cov qauv thib ob.
- Hydrophobic (hydrophilic) kev sib cuam tshuam - tshwm sim thaum polypeptide yaj hauv dej.
- Ionic attraction - tsim los ntawm cov pab pawg sib txawv ntawm cov amino acid residues (radicals).
- Covalent kev sib cuam tshuam - tuaj yeem tsim ntawm cov chaw tshwj xeeb acid - cysteine molecules, lossis theej, lawv cov tails.
Yog li, cov muaj pes tsawg leeg thiab cov qauv ntawm cov proteins nrog cov qauv tertiary tuaj yeem piav qhia raws li polypeptide chains folded rau hauv globules, tuav thiab stabilizing lawv conformation vim muaj ntau hom tshuaj sib cuam tshuam. Piv txwv ntawm xws li peptides:phosphoglycerate kenase, tRNA, alpha-keratin, silk fibroin thiab lwm yam.
Quadternary structure
Qhov no yog ib qho ntawm cov globules nyuaj tshaj plaws uas cov proteins tsim. Cov qauv thiab kev ua haujlwm ntawm cov protein ntawm hom no muaj ntau yam thiab tshwj xeeb.
Qhov kev hloov pauv no yog dab tsi? Cov no yog ob peb (qee zaum kaum ob) loj thiab me polypeptide chains uas yog tsim los ntawm ib leeg. Tab sis tom qab ntawd, vim tib qho kev sib cuam tshuam uas peb tau txiav txim siab rau cov qauv tertiary, tag nrho cov peptides twist thiab intertwine nrog ib leeg. Nyob rau hauv txoj kev no, complex conformational globules tau txais, uas muaj peev xwm muaj hlau atoms, lipid pawg, thiab carbohydrate pawg. Piv txwv ntawm cov proteins xws li: DNA polymerase, cov kab mob haus luam yeeb lub plhaub, hemoglobin, thiab lwm yam.
Txhua tus qauv peptide peb tau txiav txim siab muaj lawv tus kheej txoj hauv kev kuaj pom, raws li niaj hnub muaj peev xwm siv chromatography, centrifugation, electron thiab optical microscopy thiab high computer technologies.
Ua haujlwm
Cov qauv thiab kev ua haujlwm ntawm cov proteins sib raug zoo nrog ib leeg. Ntawd yog, txhua peptide plays lub luag haujlwm tshwj xeeb, tshwj xeeb thiab tshwj xeeb. Kuj tseem muaj cov neeg uas muaj peev xwm ua tau ntau yam haujlwm tseem ceeb hauv ib lub cell nyob ib zaug. Txawm li cas los xij, nws muaj peev xwm qhia tau nyob rau hauv daim ntawv dav dav ntawm lub luag haujlwm tseem ceeb ntawm cov protein molecules hauv cov kab mob ntawm cov tsiaj nyob:
- Txoj kev txhawb nqa. Cov kab mob ib leeg, xws li organelles, lossis qee yamhom cell muaj peev xwm txav tau, contraction, txav mus. Qhov no yog muab los ntawm cov proteins uas yog ib feem ntawm cov qauv ntawm lawv lub cev muaj zog: cilia, flagella, cytoplasmic membrane. Yog tias peb tham txog cov hlwb uas txav tsis tau, ces cov proteins tuaj yeem ua rau lawv cov leeg nqaij (muscle myosin).
- Nourishing lossis reserve function. Nws yog tsub zuj zuj ntawm cov protein molecules nyob rau hauv lub qe, embryos thiab noob ntawm cov nroj tsuag kom ntxiv ntxiv cov khoom noj uas ploj lawm. Thaum cleaved, peptides muab cov amino acids thiab biologically active tshuaj uas tsim nyog rau kev loj hlob ntawm cov kab mob nyob.
- Lub zog muaj nuj nqi. Ntxiv nrog rau cov carbohydrates, cov protein kuj tuaj yeem muab lub zog rau lub cev. Nrog rau kev tawg ntawm 1 g ntawm peptide, 17.6 kJ ntawm lub zog muaj txiaj ntsig raug tso tawm hauv daim ntawv ntawm adenosine triphosphate (ATP), uas yog siv rau cov txheej txheem tseem ceeb.
- Signal thiab tswj kev ua haujlwm. Nws muaj nyob rau hauv kev siv ceev faj tswj cov txheej txheem tsis tu ncua thiab kev sib kis ntawm cov teeb liab ntawm lub hlwb mus rau cov ntaub so ntswg, los ntawm lawv mus rau hauv nruab nrog cev, los ntawm lub tom kawg mus rau systems, thiab hais txog. Ib qho piv txwv yog insulin, uas kho cov piam thaj hauv cov ntshav kom nruj.
- Receptor muaj nuj nqi. Nws yog nqa tawm los ntawm kev hloov pauv ntawm peptide ntawm ib sab ntawm daim nyias nyias thiab koom nrog lwm qhov kawg hauv kev tsim kho. Nyob rau tib lub sijhawm, cov teeb liab thiab cov ntaub ntawv tsim nyog raug xa mus. Feem ntau, cov proteins zoo li no tau tsim rau hauv cytoplasmic daim nyias nyias ntawm cov hlwb thiab ua haujlwm nruj tswj hwm txhua yam khoom uas dhau los ntawm nws. Kuj ceeb toom txogKev hloov tshuaj lom neeg thiab lub cev hauv ib puag ncig.
- Kev thauj mus los ntawm peptides. Nws yog nqa tawm los ntawm channel cov proteins thiab carrier proteins. Lawv lub luag haujlwm yog pom tseeb - thauj cov molecules tsim nyog mus rau qhov chaw uas muaj qhov tsis tshua muaj siab los ntawm qhov chaw nrog lub siab. Ib qho piv txwv yog kev thauj cov pa oxygen thiab carbon dioxide los ntawm lub cev thiab cov ntaub so ntswg los ntawm cov protein hemoglobin. Lawv kuj nqa tawm cov khoom sib txuas nrog qhov hnyav molecular los ntawm cell membrane sab hauv.
- Structural function. Ib qho tseem ceeb tshaj plaws ntawm cov protein ua haujlwm. Cov qauv ntawm tag nrho cov cell, lawv cov organelles yog muab precisely los ntawm peptides. Lawv, zoo li ib lub thav duab, teeb cov duab thiab cov qauv. Tsis tas li ntawd, lawv txhawb nqa thiab hloov kho yog tias tsim nyog. Yog li ntawd, rau kev loj hlob thiab kev loj hlob, tag nrho cov kab mob muaj sia xav tau cov proteins hauv kev noj haus. Cov peptides no suav nrog elastin, tubulin, collagen, actin, keratin thiab lwm yam.
- Catalytic muaj nuj nqi. Enzymes ua nws. Ntau thiab ntau yam, lawv nrawm tag nrho cov tshuaj lom neeg thiab biochemical hauv lub cev. Yog tias tsis muaj lawv txoj kev koom tes, ib qho kua txiv hmab txiv ntoo hauv plab tuaj yeem zom tau hauv ob hnub nkaus xwb, nrog rau qhov muaj feem ntau ntawm rotting. Nyob rau hauv qhov kev txiav txim ntawm catalase, peroxidase thiab lwm yam enzymes, cov txheej txheem no yuav siv sij hawm ob teev. Feem ntau, nws yog ua tsaug rau lub luag hauj lwm ntawm cov proteins uas anabolism thiab catabolism tau ua, uas yog, yas thiab lub zog metabolism.
lub luag haujlwm tiv thaiv
Muaj ntau hom kev hem thawj uas cov proteins tsim los tiv thaiv lub cev.
Ua ntej, tshuajkev tawm tsam ntawm kev raug mob reagents, gases, molecules, tshuaj ntawm ntau yam spectrum ntawm kev ua. Peptides muaj peev xwm nkag mus rau hauv tshuaj lom neeg sib cuam tshuam nrog lawv, hloov mus rau hauv daim ntawv tsis muaj mob lossis tsuas yog ua rau lawv tsis zoo.
Thib ob, kev hem thawj ntawm lub cev los ntawm qhov txhab - yog tias cov protein fibrinogen tsis hloov mus ua fibrin nyob rau lub sijhawm ntawm qhov chaw raug mob, ces cov ntshav yuav tsis txhaws, uas txhais tau hais tias kev txhaws yuav tsis tshwm sim. Tom qab ntawd, ntawm qhov tsis sib xws, koj yuav xav tau plasmin peptide, uas muaj peev xwm ua kom cov ntshav txhaws thiab rov ua kom lub patency ntawm lub nkoj.
Thib peb, kev hem thawj rau kev tiv thaiv. Cov qauv thiab qhov tseem ceeb ntawm cov proteins uas tsim kev tiv thaiv kab mob yog qhov tseem ceeb heev. Cov tshuaj tiv thaiv kab mob, immunoglobulins, interferons yog txhua yam tseem ceeb thiab tseem ceeb ntawm tib neeg lymphatic thiab tiv thaiv kab mob. Txhua qhov txawv teb chaws, teeb meem molecule, tuag ib feem ntawm lub cell los yog tag nrho cov qauv yog raug mus rau tam sim ntawd kev soj ntsuam los ntawm peptide compound. Tias yog vim li cas ib tug neeg muaj peev xwm ntawm nws tus kheej, yam tsis muaj kev pab ntawm cov tshuaj, tiv thaiv nws tus kheej txhua hnub los ntawm kev kis kab mob thiab kab mob yooj yim.
Lub cev muaj zog
Cov qauv ntawm cov protein ntawm tes yog qhov tshwj xeeb thiab nyob ntawm kev ua haujlwm. Tab sis lub cev lub cev ntawm tag nrho cov peptides zoo ib yam thiab boil rau cov yam ntxwv hauv qab no.
- Qhov hnyav ntawm ib lub molecule yog txog 1,000,000 D altons.
- Colloidal systems yog tsim nyob rau hauv ib tug aqueous tov. Nyob ntawd, tus qauv tau txais tus nqi uas tuaj yeem sib txawv nyob ntawm qhov acidity ntawm ib puag ncig.
- Thaum raug mob hnyav (irradiation, acid lossis alkali, kub, thiab lwm yam), lawv tuaj yeem txav mus rau lwm theem ntawm kev sib haum xeeb, uas yogdenature. Cov txheej txheem no yog irreversible nyob rau hauv 90% ntawm cov neeg mob. Txawm li cas los xij, kuj tseem muaj qhov hloov pauv hloov pauv - renaturation.
Cov no yog cov khoom tseem ceeb ntawm lub cev yam ntxwv ntawm peptides.
