Tus lej loj ntawm ntau qhov sib xyaw ntawm ntau yam tshuaj muaj peev xwm tswj tau los ua ke tib neeg hauv chav kuaj. Txawm li cas los xij, tag nrho tib yam, tej yam ntuj tso yog, thiab yuav nyob twj ywm qhov tseem ceeb tshaj plaws thiab tseem ceeb rau lub neej ntawm tag nrho cov kab mob nyob. Ntawd yog, cov molecules uas koom nrog ntau txhiab tus biochemical tshuaj nyob rau hauv cov kab mob thiab muaj lub luag haujlwm rau lawv txoj haujlwm ib txwm muaj.
Feem coob ntawm lawv yog cov pab pawg hu ua "biological polymers".
tswvyim dav dav ntawm biopolymers
Ua ntej tshaj plaws, nws yuav tsum tau hais tias tag nrho cov khoom sib xyaw no yog cov molecular siab, muaj cov huab hwm coj mus txog ntau lab D altons. Cov tshuaj no yog tsiaj txhu thiab cov nroj tsuag polymers uas ua lub luag haujlwm txiav txim siab hauv kev tsim cov hlwb thiab lawv cov qauv, ua kom cov metabolism, photosynthesis, ua pa, khoom noj khoom haus thiab tag nrho lwm yam tseem ceeb ntawm cov kab mob muaj sia.
Nws nyuaj rau overestimate qhov tseem ceeb ntawm cov tebchaw. Biopolymers yog cov khoom ntuj tsim los ntawm lub hauv paus chiv keeb uas tsim nyob rau hauv cov kab mob nyob thiab yog lub hauv paus ntawm tag nrho lub neej nyob rau hauv peb ntiaj chaw. Dab tsi yog cov kev sib txuas tshwj xeeb rau lawvbelong?
Cell biopolymers
Muaj ntau heev. Yog li, lub ntsiab biopolymers yog raws li nram no:
- proteins;
- nucleic acids (DNA thiab RNA).
Ypolysaccharides;
Ntxiv rau lawv, qhov no kuj suav nrog ntau cov polymers sib xyaw ua ke los ntawm kev sib txuas ntawm cov uas twb tau teev tseg lawm. Piv txwv li, lipoproteins, lipopolysaccharides, glycoproteins thiab lwm yam.
Cov khoom ntiag tug
Muaj ntau ntau yam uas muaj nyob hauv txhua qhov kev txiav txim siab molecules. Piv txwv li, cov khoom nram qab no ntawm biopolymers:
- qhov hnyav molecular vim yog tsim cov macrochains loj nrog cov ceg ntoo hauv cov qauv tshuaj;
- hom kev sib cog lus hauv macromolecules (hydrogen, ionic kev sib cuam tshuam, electrostatic attraction, disulfide txuas hniav, peptide bonds thiab lwm yam);
- chav tsev ntawm txhua txoj saw yog qhov txuas monomeric;
- kev tsis sib xws lossis nws tsis nyob hauv cov qauv ntawm cov saw hlau.
Tab sis feem ntau, txhua tus biopolymers tseem muaj qhov sib txawv ntawm cov qauv thiab kev ua haujlwm ntau dua li qhov sib xws.
YProteins
Protein molecules yog qhov tseem ceeb hauv lub neej ntawm txhua tus neeg nyob. Xws li biopolymers yog lub hauv paus ntawm tag nrho cov biomass. Tseeb tiag, txawm tias raws li txoj kev xav ntawm Oparin-Haldane, lub neej hauv ntiaj teb yog los ntawm cov kua dej coacervate, uas yog cov protein.
Cov qauv ntawm cov tshuaj no yog ua raws li kev txiav txim nruj hauv cov qauv. Txhua protein yog tsim los ntawm cov amino acid residue uasmuaj peev xwm txuas mus rau ib leeg nyob rau hauv unlimited saw lengths. Qhov no tshwm sim los ntawm kev tsim cov nyiaj tshwj xeeb - peptide bonds. Xws li daim ntawv cog lus yog tsim los ntawm plaub yam: carbon, oxygen, nitrogen thiab hydrogen.
Ib qho protein molecule tuaj yeem muaj ntau cov amino acid residues, ob qho tib si thiab sib txawv (ntau txhiab txhiab lossis ntau dua). Nyob rau hauv tag nrho, muaj 20 ntau yam ntawm cov amino acids pom nyob rau hauv cov tebchaw. Txawm li cas los, lawv muaj ntau yam kev sib xyaw ua ke tso cai rau cov proteins kom vam meej nyob rau hauv ntau thiab ntau hom.
Protein biopolymers muaj qhov sib txawv ntawm qhov sib txawv. Yog li, txhua tus neeg sawv cev tuaj yeem muaj nyob hauv thawj, theem nrab, theem nrab lossis plaub tus qauv.
Qhov yooj yim tshaj plaws thiab kab ntawm lawv yog thawj qhov. Nws tsuas yog ib qho ntawm cov amino acid sequences txuas rau ib leeg.
Qhov kev hloov pauv thib ob muaj cov qauv nyuaj dua, txij li tag nrho cov macrochain ntawm cov protein pib muab kauv, tsim cov coils. Ob lub macrostructures uas nyob ib sab yog nyob ze ib leeg vim covalent thiab hydrogen kev cuam tshuam ntawm pawg ntawm lawv cov atoms. Paub qhov txawv ntawm alpha thiab beta helices ntawm cov qauv thib ob ntawm cov proteins.
Cov qauv tertiary yog ib qho macromolecule (polypeptide saw) ntawm cov protein uas dov rau hauv pob. Lub network nyuaj heev ntawm kev sib cuam tshuam hauv lub ntiaj teb no tso cai rau nws kom ruaj khov thiab ua kom nws zoo li qub.
Quaternary conformation - ob peb polypeptide chains, coiled thiab twistedrau hauv ib lub kauj, uas nyob rau tib lub sij hawm kuj tsim ntau daim ntawv cog lus ntawm ntau hom ntawm lawv tus kheej. Cov qauv globular nyuaj tshaj plaws.
Y
Kev ua haujlwm ntawm cov protein molecules
- Tsheb thauj mus los. Nws yog ua los ntawm cov protein hlwb uas ua rau lub plasma membrane. Lawv tsim cov ion channel uas qee cov molecules muaj peev xwm dhau mus. Tsis tas li ntawd, ntau cov proteins yog ib feem ntawm cov organelles ntawm kev txav ntawm protozoa thiab cov kab mob, yog li lawv tau koom ncaj qha rau lawv txoj kev txav.
- Lub zog muaj nuj nqi yog ua los ntawm cov molecules nquag heev. Ib gram ntawm cov protein nyob rau hauv cov txheej txheem ntawm cov metabolism hauv 17.6 kJ ntawm lub zog. Yog li ntawd, kev noj cov nroj tsuag thiab tsiaj cov khoom uas muaj cov tebchaw no tseem ceeb heev rau cov kab mob nyob.
- Lub tsev muaj nuj nqi yog kev koom tes ntawm cov protein molecules hauv kev tsim kho ntawm cov cellular feem ntau, cov hlwb lawv tus kheej, cov ntaub so ntswg, lub cev, thiab lwm yam. Yuav luag txhua lub xovtooj ntawm tes yog tsim los ntawm cov molecules (cytoskeleton ntawm cytoplasm, plasma membrane, ribosome, mitochondria thiab lwm yam qauv koom nrog hauv kev tsim cov protein sib txuas).
- Lub luag haujlwm catalytic yog ua los ntawm enzymes, uas los ntawm lawv cov tshuaj tsis muaj dab tsi ntau dua li cov protein. Yog tsis muaj enzymes, feem ntau cov tshuaj biochemical hauv lub cev yuav ua tsis tau, vim tias lawv yog cov tshuaj lom neeg hauv lub cev.
- Receptor (kuj taw qhia) ua haujlwm pab cov hlwb taug qab thiab teb kom raug rau txhua qhov kev hloov pauv hauv ib puag ncig, xws limechanical thiab chemical.
Yog tias peb xav txog cov protein ntau qhov tob, peb tuaj yeem hais txog qee qhov kev ua haujlwm thib ob. Txawm li cas los xij, cov npe teev yog cov tseem ceeb.
Nucleic acids
Cov biopolymers zoo li no yog ib feem tseem ceeb ntawm txhua lub cell, tsis hais nws prokaryotic lossis eukaryotic. Tseeb tiag, nucleic acids suav nrog DNA (deoxyribonucleic acid) thiab RNA (ribonucleic acid) molecules, txhua qhov yog qhov txuas tseem ceeb heev rau cov tsiaj nyob.
Los ntawm lawv cov tshuaj lom neeg, DNA thiab RNA yog cov kab ke ntawm nucleotides txuas nrog hydrogen bonds thiab phosphate choj. DNA yog tsim los ntawm nucleotides xws li:
- adenine;
- thymine;
- guanine;
- cytosine;
- 5-carbon qab zib deoxyribose.
RNA txawv ntawm qhov thymine hloov los ntawm uracil, thiab qab zib los ntawm ribose.
Vim lub koom haum tshwj xeeb ntawm DNA molecules muaj peev xwm ua tau ntau yam haujlwm tseem ceeb. RNA kuj tseem ua lub luag haujlwm loj hauv cell.
Function of xws acids
Nucleic acids yog biopolymer lub luag haujlwm rau cov haujlwm hauv qab no:
- DNA yog lub khw thiab xa cov ntaub ntawv caj ces hauv cov hlwb ntawm cov kab mob muaj sia. Hauv prokaryotes, cov molecule no tau muab faib rau hauv cytoplasm. Nyob rau hauv ib lub cell eukaryotic, nws nyob rau hauv lub nucleus, sib cais los ntawm ib tug karyolemma.
- DNA molecule muab faib ua ob ntu - cov noob uas tsim cov qauv ntawm cov chromosome. Txhua tus noobcreatures tsim ib tug tshwj xeeb genetic code nyob rau hauv uas tag nrho cov cim qhia ntawm lub cev yog encrypted.
- RNA yog peb hom - qauv, ribosomal thiab thauj. Ribosomal koom nrog hauv kev sib txuas thiab sib sau ua ke ntawm cov protein molecules ntawm cov qauv sib xws. Matrix thiab thauj cov ntaub ntawv hloov pauv tau nyeem los ntawm DNA thiab txiav txim siab nws lub ntsiab lus lom neeg.
YPolysaccharides
Cov tebchaw no feem ntau yog cov nroj tsuag polymers, uas yog, lawv pom tseeb hauv cov hlwb ntawm cov neeg sawv cev ntawm cov nroj tsuag. Lawv cov phab ntsa ntawm tes, uas muaj cellulose, tshwj xeeb tshaj yog nplua nuj nyob rau hauv polysaccharides.
Los ntawm lawv cov tshuaj lom neeg, polysaccharides yog cov carbohydrate complex macromolecules. Lawv tuaj yeem yog linear, txheej, sib txuas sib txuas. Monomers yog yooj yim tsib-, feem ntau rau-carbon suab thaj - ribose, qabzib, fructose. Lawv yog ib qho tseem ceeb heev rau cov tsiaj muaj sia, vim lawv yog ib feem ntawm lub hlwb, lawv yog cov khoom noj tshwj xeeb rau cov nroj tsuag, lawv tau tawg nrog kev tso tawm ntau lub zog.
Lub ntsiab lus ntawm ntau tus neeg sawv cev
Cov khoom siv roj ntsha xws li cov hmoov txhuv nplej siab, cellulose, inulin, glycogen, chitin thiab lwm yam tseem ceeb heev. Lawv yog lub hauv paus tseem ceeb ntawm lub zog ntawm cov kab mob nyob.
Yog li, cellulose yog ib qho tseem ceeb ntawm cov phab ntsa ntawm cov nroj tsuag, qee cov kab mob. Muab lub zog, ib qho zoo li. Hauv kev lag luam, tus txiv neej yog siv kom tau daim ntawv, muaj txiaj ntsig acetate fibers.
Starch yog ib qho chaw cia khoom noj,uas kuj yog ib qho khoom noj muaj txiaj ntsig rau tib neeg thiab tsiaj.
Glycogen, lossis tsiaj rog, yog cov khoom noj tshwj xeeb rau tsiaj thiab tib neeg. Ua haujlwm ntawm thermal rwb thaiv tsev, lub zog qhov chaw, tiv thaiv txhua yam.
Mixed biopolymers nyob rau hauv creatures
Ntxiv rau cov uas peb tau txiav txim siab, muaj ntau qhov sib xyaw ua ke ntawm macromolecular compounds. Xws li biopolymers yog cov sib xyaw ua ke ntawm cov protein thiab lipids (lipoproteins) lossis polysaccharides thiab cov proteins (glycoproteins). Kev sib xyaw ntawm lipids thiab polysaccharides (lipopolysaccharides) kuj tseem ua tau.
Txhua yam ntawm cov biopolymers no muaj ntau yam uas ua tau ntau lub luag haujlwm tseem ceeb hauv cov tsiaj muaj sia: thauj, taw qhia, receptor, kev tswj hwm, enzymatic, tsev thiab ntau lwm yam. Lawv cov qauv yog chemically complex thiab deb ntawm kev deciphered rau tag nrho cov neeg sawv cev, yog li ntawd, lub luag hauj lwm tsis tau txhais tag nrho. Niaj hnub no, tsuas yog cov neeg paub ntau tshaj plaws, tab sis ib feem tseem ceeb tseem nyob dhau ntawm thaj tsam ntawm tib neeg kev paub.
