Muaj plaub chav kawm tseem ceeb tshaj plaws ntawm cov organic tebchaw uas ua rau lub cev: nucleic acids, rog, carbohydrates thiab proteins. Qhov kawg yuav tau tham hauv kab lus no.
Y Yuav ua li cas yog protein?
Cov no yog cov tshuaj polymeric tshuaj ua los ntawm cov amino acids. Proteins muaj ib tug complex qauv.
Yuav ua li cas protein synthesized?
Nws tshwm sim hauv cov hlwb ntawm lub cev. Muaj cov organelles tshwj xeeb uas yog lub luag haujlwm rau cov txheej txheem no. Cov no yog ribosomes. Lawv muaj ob ntu: me me thiab loj, uas tau ua ke thaum lub sijhawm ua haujlwm ntawm organelle. Cov txheej txheem ntawm synthesizing ib tug polypeptide saw los ntawm cov amino acids yog hu ua translation.
YAmino acids yog dab tsi?
Txawm hais tias muaj ntau ntau hom proteins hauv lub cev, tsuas muaj nees nkaum amino acids uas lawv tuaj yeem tsim tau. Xws li ntau yam ntawm cov proteins yog ua tiav vim qhov sib txawv ntawm kev sib xyaw ua ke thiab cov kab ke ntawm cov amino acids no, nrog rau kev sib txawv ntawm cov saw hlau tsim hauv qhov chaw.
Amino acids muaj nyob rau hauv lawv cov tshuaj muaj pes tsawg leeg ob pawg ua haujlwm tawm tsam hauv lawv cov khoom:carboxyl thiab amino pawg, nrog rau cov radical: aromatic, aliphatic lossis heterocyclic. Tsis tas li ntawd, cov radicals yuav muaj cov pab pawg ua haujlwm ntxiv. Cov no tuaj yeem yog pawg carboxyl, pawg amino, amide, hydroxyl, guanide pawg. Cov radical kuj tseem muaj cov sulfur.
Ntawm no yog cov npe ntawm cov kua qaub uas cov proteins tuaj yeem tsim tau:
- alanine;
- glycine;
- leucine;
- valine;
- isoleucine;
- threonine;
- serine;
- glutamic acid;
- aspartic acid;
- glutamine;
- asparagine;
- arginine;
- lysine;
- methionine;
- cysteine;
- tyrosine;
- phenylalanine;
- histidine;
- tryptophan;
- proline.
Ntawm cov no, kaum yog qhov hloov tsis tau - cov uas tsis tuaj yeem ua rau tib neeg lub cev. Cov no yog valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, histidine, arginine. Lawv yuav tsum tau noj nrog zaub mov. Ntau cov amino acids no muaj nyob hauv ntses, nqaij nyuj, nqaij, txiv ntseej, legumes.
Tus qauv thawj ntawm cov protein - nws yog dab tsi?
Qhov no yog qhov sib lawv liag ntawm cov amino acids hauv cov saw hlau. Paub txog cov qauv tseem ceeb ntawm cov protein, nws muaj peev xwm kos nws cov qauv tshuaj lom neeg.
qauv tsev kawm theem nrab
Qhov no yog ib txoj hauv kev los twist cov saw hlau polypeptide. Muaj ob qhov sib txawv ntawm kev teeb tsa cov protein: alpha helix thiab beta qauv. Cov qauv thib ob ntawm cov protein yog muabhydrogen bonds ntawm CO thiab NH pawg.
Tertiary protein qauv
Qhov no yog qhov kev taw qhia spatial ntawm tus kauv lossis txoj hauv kev uas nws muab tso rau hauv ib lub ntim. Nws yog muab los ntawm disulfide thiab peptide tshuaj bonds.
Nyob ntawm seb hom qauv tertiary, muaj fibrillar thiab globular proteins. Cov tom kawg yog spherical nyob rau hauv cov duab. Cov qauv ntawm fibrillar proteins zoo ib yam li cov xov, uas yog tsim los ntawm stacking beta cov qauv los yog kev sib txuas ntawm ob peb alpha qauv.
Quadternary structure
Nws yog tus yam ntxwv ntawm cov proteins uas tsis muaj ib qho, tab sis ob peb cov saw hlau polypeptide. Cov proteins no hu ua oligomeric. Cov chains ib tug neeg uas ua rau lawv muaj pes tsawg leeg yog hu ua protomers. Cov protomers uas tsim ib qho oligomeric protein tuaj yeem muaj tib yam lossis sib txawv hauv thawj, theem nrab, lossis qib theem.
Dab tsi yog qhov tseeb?
Qhov no yog kev puas tsuaj ntawm quaternary, tertiary, theem nrab ntawm cov protein, vim nws poob nws cov tshuaj, lub cev thiab tsis tuaj yeem ua tiav nws lub luag haujlwm hauv lub cev. Cov txheej txheem no tuaj yeem tshwm sim los ntawm qhov kub thiab txias ua rau cov protein (los ntawm 38 degrees Celsius, tab sis daim duab no yog ib tus neeg rau txhua tus protein) lossis cov khoom hnyav xws li acids thiab alkalis.
Qee cov proteins muaj peev xwm ntawm renaturation - rov ua dua tshiab ntawm lawv cov qauv qub.
YProtein classification
Muab cov tshuaj muaj pes tsawg leeg, lawv muab faib ua yooj yim thiab complex.
Cov proteins yooj yim (proteins) yog cov uas muaj cov amino acids nkaus xwb.
Cov proteins tsis sib haum (proteids) - cov uas muaj cov pab pawg prosthetic hauv lawv cov muaj pes tsawg leeg.
Nyob ntawm cov pab pawg neeg prosthetic, cov proteins tuaj yeem muab faib ua:
- lipoproteins (muaj lipids);
- nucleoproteins (muaj nucleic acids);
- chromoproteins (muaj cov xim);
- phosphoproteins (muaj phosphoric acid nyob rau hauv lawv cov muaj pes tsawg leeg);
- metalloproteins (muaj hlau);
- glycoproteins (muaj carbohydrates).
Ntxiv rau, nyob ntawm seb hom qauv tertiary, muaj globular thiab fibrillar protein. Ob leeg tuaj yeem yooj yim lossis nyuaj.
Cov khoom ntawm fibrillar proteins thiab lawv lub luag haujlwm hauv lub cev
Lawv tuaj yeem muab faib ua peb pawg nyob ntawm tus qauv thib ob:
- Alpha qauv. Cov no suav nrog keratins, myosin, tropomyosin thiab lwm yam.
- Beta qauv. Piv txwv li, fibroin.
- Y Collagen. Nws yog cov protein uas muaj cov qauv tshwj xeeb thib ob uas tsis yog alpha helix lossis beta qauv.
Cov yam ntxwv ntawm fibrillar proteins ntawm tag nrho peb pawg yog tias lawv muaj cov qauv filamentous tertiary thiab tseem insoluble hauv dej.
Cia tham txog lub ntsiab fibrillar proteins kom ntxaws ntxiv nyob rau hauv kev txiav txim:
- Keratins. Qhov no yog tag nrho pawg ntawm ntau yam proteins uas yog lub ntsiab ntawm cov plaub hau, rau tes, plaub, ntaub plaub, horns, hooves, thiab lwm yam. Tsis tas li ntawd, fibrillar protein ntawm pab pawg no, cytokeratin, yog ib feem ntawm cov hlwb, tsim cov cytoskeleton.
- Myosin. Qhov no yog ib yam khoom uas yog ib feem ntawm cov nqaij fibers. Nrog rau actin, qhov no fibrillar protein yog contractile thiab ua kom cov leeg ua haujlwm.
- Tropomyosin. Cov khoom no muaj ob qhov sib txuas ntawm alpha helices. Nws kuj yog ib feem ntawm cov leeg.
- Fibroin. Cov protein no yog zais los ntawm ntau kab thiab arachnids. Nws yog cov khoom tseem ceeb ntawm lub vev xaib thiab txhob lo lo ntxhuav.
- Y Collagen. Nws yog cov protein ntau fibrillar hauv tib neeg lub cev. Nws yog ib feem ntawm cov leeg, pob txha mos, cov leeg, cov hlab ntsha, tawv nqaij, thiab lwm yam. Cov khoom no muab cov ntaub so ntswg elasticity. Collagen ntau lawm hauv lub cev poob qis nrog lub hnub nyoog, ua rau daim tawv nqaij wrinkles, tsis muaj zog ntawm tendons thiab ligaments, thiab lwm yam.
Tom ntej, xav txog pawg thib ob ntawm cov proteins.
Globular proteins: ntau yam, khoom thiab lub luag haujlwm lom neeg
Cov khoom ntawm pawg no muaj cov duab ntawm lub pob. Lawv tuaj yeem soluble hauv dej, daws cov alkalis, ntsev thiab acids.
Cov protein ntau tshaj plaws hauv lub cev yog:
- Albumins: ovalbumin, lactalbumin, thiab lwm yam.
- Globulins: ntshav proteins (xws li hemoglobin, myoglobin), thiab lwm yam.
Ntau yam ntawm lawv:
- Ovalbumin. Cov protein no yog 60 feem pua ntawm qe dawb.
- Lactalbumin. Cov ntsiab lus tseem ceeb ntawm cov mis nyuj.
- hemoglobin. Nws yog complexglobular protein, uas muaj heme raws li ib pab pawg neeg prosthetic, yog ib pawg pigment muaj hlau. Hemoglobin muaj nyob hauv cov qe ntshav liab. Nws yog cov protein uas tuaj yeem khi rau oxygen thiab thauj nws.
- Myoglobin. Nws yog cov protein zoo ib yam li hemoglobin. Nws ua haujlwm tib yam - nqa oxygen. Xws li cov protein muaj nyob rau hauv cov leeg (striated thiab cardiac).
Tam sim no koj paub qhov sib txawv ntawm qhov yooj yim thiab nyuaj, fibrillar thiab globular proteins.
