A macromolecule yog ib qho molecule uas muaj qhov hnyav molecular. Nws cov qauv yog nthuav tawm nyob rau hauv daim ntawv ntawm kev rov ua dua txuas ntxiv. Xav txog cov yam ntxwv ntawm cov khoom sib txuas, lawv qhov tseem ceeb rau lub neej ntawm cov tsiaj nyob.
Txoj kev sib sau
Kev lom neeg macromolecules yog tsim los ntawm ntau pua txhiab ntawm cov khoom pib me me. Cov kab mob muaj sia nyob muaj peb hom macromolecules: cov proteins, polysaccharides, nucleic acids.
thawj monomers rau lawv yog monosaccharides, nucleotides, amino acids. Ib qho macromolecule yog yuav luag 90 feem pua ntawm cov cell loj. Nyob ntawm seb muaj pes tsawg tus amino acid residues, ib qho protein molecule yog tsim.
High molecular hnyav yog cov tshuaj uas muaj molar loj dua 103 Da.
History of the term
Thaum twg macromolecule tshwm sim? Lub tswv yim no tau qhia los ntawm Nobel Laureate hauv Chemistry Hermann Staudinger hauv xyoo 1922.
Lub pob polymer tuaj yeem pom tau tias yog cov xov tangled uas tau tsim los ntawm kev sib tsoothoob plaws hauv chav coil. Qhov no coil systematically hloov nws conformation; qhov no yog spatial configuration ntawm macromolecule. Nws zoo ib yam li txoj hauv kev ntawm Brownian motion.
Qhov kev tsim ntawm cov kauj no tshwm sim vim qhov tseeb tias ntawm qhov deb ntawm cov khoom siv polymer "poob" cov ntaub ntawv hais txog kev taw qhia. Nws muaj peev xwm tham txog ib co coil nyob rau hauv rooj plaub thaum high-molecular tebchaw yog ntev npaum li cas nyob rau hauv ntev tshaj li qhov ntev ntawm lub structural fragment.
Ntiaj teb configuration
A macromolecule yog qhov sib txawv ntom ntom uas ib tus tuaj yeem sib piv qhov ntim feem ntawm cov polymer nrog ib chav tsev. Lub xeev globular tau pom zoo nyob rau hauv cov xwm txheej no thaum, nyob rau hauv kev sib koom ua ke ntawm ib tus neeg polymer units ntawm lawv tus kheej thiab ib puag ncig sab nraud, kev sib nrig sib nyiam tshwm sim.
Ib qho piv txwv ntawm cov qauv ntawm macromolecule yog ib feem ntawm cov dej uas tau kos los ua ib qho ntawm cov qauv zoo li no. Nws yog qhov ze tshaj plaws hydration ib puag ncig ntawm macromolecule.
Tus yam ntxwv ntawm cov protein molecule
Protein macromolecules yog cov tshuaj hydrophilic. Thaum cov protein qhuav tau yaj hauv dej, nws pib swells, tom qab ntawd maj mam hloov mus rau hauv kev daws teeb meem. Thaum o, dej molecules nkag mus rau hauv cov protein, khi nws cov qauv nrog cov pawg polar. Qhov no loosens cov ntim ntom ntom ntawm cov saw hlau polypeptide. Ib qho o ntawm cov protein molecule yog suav tias yog ib qho kev daws teeb meem rov qab. Nrog rau tom qab nqus dej molecules, kev sib cais ntawm cov protein molecules los ntawm tag nrho cov huab hwm coj yog pom, thiabtseem muaj txoj kev tawg.
Tab sis qhov o ntawm cov protein molecule tsis nyob rau hauv txhua rooj plaub ua rau tawg. Piv txwv li, collagen tom qab nqus dej molecules tseem nyob hauv lub xeev o.
Hydrate theory
High-molecular compounds raws li txoj kev xav no tsis yog tsuas yog adsorb xwb, tab sis electrostatically khi cov dej molecules nrog lub ncov qaumteb qabteb ntawm sab radicals ntawm cov amino acids uas muaj tus nqi tsis zoo, nrog rau cov amino acids yooj yim uas nqa cov nqi zoo.
Cov dej ib nrab yog khi los ntawm cov pab pawg peptide uas tsim hydrogen bonds nrog dej molecules.
Piv txwv li, polypeptides uas muaj cov pab pawg tsis-polar swell. Thaum khi rau cov pab pawg peptide, nws thawb lub polypeptide chains sib nrug. Lub xub ntiag ntawm interchain txuas hniav tsis tso cai rau cov protein molecules kom tawg tag, mus rau hauv daim ntawv ntawm kev daws teeb meem.
Cov qauv ntawm macromolecules raug rhuav tshem thaum cua sov, ua rau tawg thiab tso tawm ntawm cov saw hlau polypeptide.
Ntse ntawm gelatin
Cov tshuaj muaj pes tsawg leeg ntawm gelatin zoo ib yam li collagen, nws tsim cov kua nplaum nrog dej. Ntawm cov yam ntxwv ntawm gelatin yog nws lub peev xwm ua gel.
Cov hom molecules no yog siv los ua hemostatic thiab plasma-substituting agents. Lub peev xwm ntawm gelatin los tsim cov gels yog siv los tsim cov tshuaj ntsiav hauv kev lag luam tshuaj.
Solubility featuremacromolecules
Cov hom molecules no muaj qhov sib txawv hauv dej. Nws yog txiav txim los ntawm cov amino acid muaj pes tsawg leeg. Nyob rau hauv lub xub ntiag ntawm polar amino acids nyob rau hauv cov qauv, lub peev xwm rau yaj nyob rau hauv dej nce ho.
Tsis tas li ntawd, cov cuab yeej no cuam tshuam los ntawm qhov peculiarity ntawm lub koom haum ntawm macromolecule. Globular proteins muaj solubility ntau dua li fibrillar macromolecules. Nyob rau hauv chav kawm ntawm ntau qhov kev sim, qhov kev cia siab ntawm kev sib cais ntawm cov yam ntxwv ntawm cov kuab tshuaj siv tau raug tsim.
Cov qauv tseem ceeb ntawm txhua tus qauv ntawm cov protein sib txawv, uas muab cov khoom muaj protein ntau. Lub xub ntiag ntawm cross-links ntawm polypeptide chains txo solubility.
Cov qauv ntawm cov protein molecules yog tsim los ntawm peptide (amide) bonds; thaum nws raug rhuav tshem, protein denaturation tshwm sim.
Txhawm rau kom cov kuab tshuaj molecules muaj protein ntau, kev daws cov ntsev nruab nrab yog siv. Piv txwv li, nyob rau hauv ib txoj kev zoo sib xws, xaiv nag lossis daus ntawm cov protein tuaj yeem ua tiav, lawv cov fractionation tuaj yeem ua tiav. Qhov tshwm sim ntawm cov molecules nyob ntawm qhov pib muaj pes tsawg leeg ntawm qhov sib tov.
Qhov peculiarity ntawm cov proteins, uas tau los ntawm kev s alting tawm, yog khaws cia ntawm cov yam ntxwv lom tom qab ua tiav cov ntsev.
Lub ntsiab ntawm cov txheej txheem yog tshem tawm los ntawm anions thiab cations ntawm ntsev ntawm hydrated protein plhaub, uas ua kom muaj kev ruaj ntseg ntawm macromolecule. Qhov siab tshaj plaws ntawm cov protein molecules yog s alted tawm thaum siv sulfates. Txoj kev no yog siv los ntxuav thiab cais cov protein macromolecules, vim lawv yog qhov tseem ceebQhov sib txawv ntawm qhov loj ntawm tus nqi, qhov ntsuas ntawm lub plhaub hydration. Txhua cov protein muaj nws tus kheej s alting tawm tsam, uas yog, rau nws koj yuav tsum tau xaiv ntsev ntawm ib tug muab concentration.
Amino acids
Tam sim no, txog ob puas amino acids paub tias yog ib feem ntawm cov protein molecules. Nyob ntawm tus qauv, lawv muab faib ua ob pawg:
- proteinogenic, uas yog ib feem ntawm macromolecules;
- non-proteinogenic, tsis koom tes hauv kev tsim cov proteins.
Cov kws tshawb fawb tau tswj xyuas qhov sib lawv liag ntawm cov amino acids hauv ntau cov protein molecules ntawm tsiaj thiab cov nroj tsuag keeb kwm. Ntawm cov amino acids uas feem ntau pom muaj nyob rau hauv muaj pes tsawg leeg ntawm cov protein molecules, peb nco ntsoov serine, glycine, leucine, alanine. Txhua yam biopolymer muaj nws tus kheej cov amino acid muaj pes tsawg leeg. Piv txwv li, protamines muaj txog 85 feem pua arginine, tab sis lawv tsis muaj acidic, cyclic amino acids. Fibroin yog ib qho protein molecule ntawm ntuj txhob lo lo ntxhuav, uas muaj li ib nrab ntawm cov glycine. Collagen muaj xws li cov amino acids tsis tshua muaj xws li hydroxyproline, hydroxylysine, uas tsis muaj nyob rau hauv lwm cov protein macromolecules.
Amino acid muaj pes tsawg leeg yog txiav txim siab tsis yog los ntawm cov yam ntxwv ntawm cov amino acids, tab sis kuj los ntawm kev ua haujlwm thiab lub hom phiaj ntawm cov protein macromolecules. Lawv cov kab ke yog txiav txim los ntawm txoj cai caj ces.
Levels of structural organization of biopolymers
Nws muaj plaub theem: thawj, theem nrab, theem nrab, thiab plaub theem. Txhua tus qauvmuaj cov yam ntxwv txawv.
Cov qauv tseem ceeb ntawm cov protein molecules yog cov kab polypeptide kab ntawm cov amino acid residue txuas los ntawm peptide bonds.
Nws yog cov qauv no uas ruaj khov tshaj plaws, vim nws muaj peptide covalent bonds ntawm pawg carboxyl ntawm ib cov amino acid thiab cov amino pawg ntawm lwm cov molecule.
Cov qauv thib ob cuam tshuam nrog kev sib txuas ntawm cov saw hlau polypeptide nrog kev pab ntawm hydrogen bonds hauv daim ntawv helical.
Hom tertiary ntawm biopolymer yog tau los ntawm kev ntim khoom ntawm polypeptide. Lawv subdivide kauv thiab txheej-folded cov ntaub ntawv ntawm tertiary lug.
Cov proteins thoob ntiaj teb muaj cov duab elliptical, thaum fibrillar molecules muaj cov duab elongated.
Yog tias ib lub macromolecule tsuas muaj ib txoj hlua polypeptide xwb, cov protein tsuas muaj cov qauv tertiary xwb. Piv txwv li, nws yog cov nqaij leeg nqaij protein (myoglobin) uas tsim nyog rau kev sib txuas cov pa oxygen. Qee cov biopolymers tau tsim los ntawm ob peb cov saw hlau polypeptide, txhua tus muaj cov qauv tertiary. Hauv qhov no, macromolecule muaj cov qauv quaternary, muaj ntau lub globules ua ke rau hauv cov qauv loj. Hemoglobin tuaj yeem suav hais tias tsuas yog quaternary protein uas muaj txog 8 feem pua histidine. Nws yog nws leej twg yog ib qho active intracellular tsis nyob rau hauv erythrocytes, uas tso cai rau tuav ib tug ruaj khov pH nqi ntawm cov ntshav.
Nucleic acids
Lawv yog cov tshuaj macromolecular uas tsim los ntawm cov khoom tawgnucleotides. RNA thiab DNA muaj nyob hauv txhua lub hlwb nyob, lawv ua haujlwm ntawm kev khaws cia, xa tawm, thiab siv cov ntaub ntawv keeb kwm yav dhau los. Nucleotides ua raws li monomers. Txhua ntawm lawv muaj cov seem ntawm nitrogenous puag, carbohydrate, thiab kuj phosphoric acid. Cov kev tshawb fawb tau pom tias lub hauv paus ntsiab lus ntawm complementarity (complementarity) tau pom nyob rau hauv DNA ntawm cov kab mob sib txawv. Nucleic acids yog soluble hauv dej tab sis insoluble hauv organic solvents. Cov biopolymers no raug rhuav tshem los ntawm qhov kub thiab txias, hluav taws xob ultraviolet.
Siv qhov xaus
Ntxiv rau ntau yam proteins thiab nucleic acids, carbohydrates yog macromolecules. Polysaccharides nyob rau hauv lawv muaj pes tsawg leeg muaj pua pua ntawm monomers, uas muaj ib tug qab ntxiag qab zib saj. Piv txwv ntawm cov qauv hierarchical ntawm macromolecules muaj xws li cov molecules loj ntawm cov proteins thiab nucleic acids nrog complex subunits.
Piv txwv li, cov qauv spatial ntawm globular protein molecule yog qhov tshwm sim ntawm lub koom haum hierarchical multilevel ntawm amino acids. Muaj kev sib raug zoo ntawm tus kheej theem, cov ntsiab lus ntawm qib siab yog txuas nrog cov txheej txheem qis.
Txhua biopolymers ua haujlwm tseem ceeb zoo sib xws. Lawv yog cov khoom siv hauv tsev rau cov hlwb nyob, yog lub luag haujlwm rau kev khaws cia thiab xa cov ntaub ntawv keeb kwm yav dhau los. Txhua tus neeg nyob yog tus cwj pwm los ntawm cov proteins tshwj xeeb, yog li biochemists ntsib txoj haujlwm nyuaj thiab lub luag haujlwm, daws qhov uas lawv cawm cov kab mob muaj sia los ntawm qee qhov kev tuag.
