Enzymes yog globular proteins uas pab tag nrho cov txheej txheem ntawm tes ua haujlwm. Zoo li txhua tus catalysts, lawv tsis tuaj yeem thim rov qab cov tshuaj tiv thaiv, tab sis ua haujlwm kom nrawm.
Localization ntawm enzymes hauv cell
Hauv lub xovtooj ntawm tes, ib tus neeg enzymes feem ntau muaj thiab ua haujlwm hauv cov kab mob nruj me ntsis. Qhov chaw ntawm cov enzymes ncaj qha cuam tshuam nrog kev ua haujlwm uas feem ntau ntawm tes ua haujlwm.
Y Yuav luag tag nrho cov glycolysis enzymes nyob hauv cytoplasm. Enzymes ntawm lub voj voog tricarboxylic acid yog nyob rau hauv mitochondrial matrix. Cov tshuaj nquag ntawm hydrolysis muaj nyob hauv lysosomes.
Cov ntaub so ntswg thiab kab mob ntawm cov tsiaj thiab cov nroj tsuag txawv tsis tau tsuas yog nyob rau hauv cov enzymes, tab sis kuj nyob rau hauv lawv cov dej num. Cov yam ntxwv ntawm cov ntaub so ntswg no yog siv hauv tsev kho mob hauv kev kuaj mob ntawm qee yam kab mob.
Tseem muaj cov yam ntxwv ntsig txog hnub nyoog hauv kev ua haujlwm thiab cov enzymes hauv cov ntaub so ntswg. Lawv pom tseeb tshaj plaws thaum lub sij hawm embryonic txoj kev loj hlob thaum lub sij hawm cov ntaub so ntswg sib txawv.
Enzyme npe
Muaj ntau lub npe hu ua, txhua tus yuav siv rau hauv tus account lub zog ntawm enzymes mus rau qhov sib txawv.
- Tshuaj. Cov npe ntawm cov khoom raug muab random. Piv txwv li, pepsin (pepsis - "kev zom zaub mov", Greek) thiab trypsin (tripsis - "thin", Greek)
- Rational. Lub npe ntawm cov enzyme muaj cov substrate thiab xaus "-ase". Piv txwv li, amylase accelerates hydrolysis ntawm starch (amylo - "starch", Greek).
- Moscow. Nws tau txais kev pom zoo hauv 1961 los ntawm International Commission ntawm Enzyme Nomenclature ntawm 5th International Congress of Biochemistry. Lub npe ntawm cov khoom yog tsim los ntawm cov substrate thiab cov tshuaj tiv thaiv uas yog catalyzed (nrawm) los ntawm cov enzyme. Yog hais tias lub luag haujlwm ntawm enzymes yog hloov ib pab pawg ntawm cov atoms los ntawm ib lub molecule (substrate) mus rau lwm tus (acceptor), lub npe ntawm cov catalyst suav nrog cov tshuaj npe ntawm tus neeg txais. Piv txwv li, nyob rau hauv cov tshuaj tiv thaiv ntawm kev hloov cov amino pawg los ntawm alanine mus rau 2-hydroxyglutaric acid, enzyme alanine: 2-oxoglutarate aminotransferase koom nrog. Lub npe cuam tshuam:
- substrate - alanine;
- txais - 2-oxoglutaric acid;
- ib pawg amino yog pauv hauv cov tshuaj tiv thaiv.
Lub Tuam Txhab Thoob Ntiaj Teb tau sau cov npe ntawm txhua tus paub cov enzymes, uas tau hloov kho tas li. Qhov no yog vim kev tshawb pom cov tshuaj tshiab.
Kev faib tawm ntawm enzymes
Muaj ob txoj hauv kev los faib cov enzymes rau hauv pab pawg. Thawj muaj ob chav kawm ntawm cov tshuaj no:
- simple - muaj cov protein xwb;
- complex - muaj ib feem ntawm cov protein (apoenzyme) thiab ib feem tsis yog protein hu ua coenzyme.
Nyob rau hauv qhov tsis yog-proteincomplex enzyme tej zaum yuav muaj cov vitamins. Kev sib cuam tshuam nrog lwm yam tshuaj tshwm sim los ntawm qhov chaw ua haujlwm. Tag nrho cov enzyme molecule tsis koom nrog hauv cov txheej txheem.
Cov khoom ntawm enzymes, zoo li lwm cov proteins, yog txiav txim los ntawm lawv cov qauv. Nyob ntawm nws, cov catalysts nrawm tsuas yog lawv cov tshuaj tiv thaiv.
Txoj kev thib ob ntawm kev faib tawm faib cov tshuaj raws li kev ua haujlwm ntawm enzymes. Qhov tshwm sim yog rau chav kawm:
- oxidoreductase;
- transferases;
- Yhydrolases;
- isomerase;
- lyases;
- ligases.
Cov no feem ntau lees txais cov pab pawg, lawv txawv tsis yog hauv hom kev cuam tshuam uas tswj cov enzymes hauv lawv. Cov khoom ntawm cov pab pawg sib txawv muaj cov qauv sib txawv. Thiab cov haujlwm ntawm cov enzymes hauv ib lub cell, yog li ntawd, tsis tuaj yeem zoo ib yam.
Oxidoreductases - redox
Lub luag haujlwm tseem ceeb ntawm cov enzymes ntawm thawj pab pawg yog qhov nrawm ntawm cov tshuaj tiv thaiv redox. Ib tug yam ntxwv feature: lub peev xwm los tsim chains ntawm oxidative enzymes nyob rau hauv uas electrons los yog hydrogen atoms yog pauv los ntawm thawj heev substrate mus rau qhov kawg txais. Cov tshuaj no raug cais raws li lub hauv paus ntsiab lus ntawm kev ua haujlwm lossis qhov chaw ua haujlwm hauv cov tshuaj tiv thaiv.
- Aerobic dehydrogenases (oxidases) ua kom nrawm hloov ntawm electrons lossis protons ncaj qha mus rau oxygen atoms. Anaerobic sawv daws ua tib yam nkaus, tab sis nyob rau hauv cov kev tshwm sim uas tsis tau hloov ntawm electrons los yog hydrogen atoms rau oxygen atoms.
- Pibdehydrogenases catalyze cov txheej txheem ntawm tshem tawm hydrogen atoms los ntawm oxidized tshuaj (thawj substrate). Secondary - ceev tshem tawm cov hydrogen atoms los ntawm lub substrate theem nrab, lawv tau txais kev siv thawj dehydrogenase.
Lwm qhov tshwj xeeb: ua ob lub ntsiab lus catalysts nrog cov coenzymes tsawg heev (cov pab pawg nquag), lawv tuaj yeem ua kom muaj ntau yam kev cuam tshuam redox. Qhov no ua tiav los ntawm ntau txoj kev xaiv: tib coenzyme tuaj yeem koom nrog apoenzymes sib txawv. Hauv txhua kis, qhov tshwj xeeb oxidoreductase tau txais nrog nws cov khoom.
Muaj lwm txoj haujlwm ntawm cov enzymes ntawm pab pawg no, uas tsis tuaj yeem tsis quav ntsej - lawv ua kom cov txheej txheem tshuaj lom neeg cuam tshuam nrog kev tso tawm ntawm lub zog. Cov tshuaj tiv thaiv zoo li no hu ua exothermic.
Kev hloov pauv - cov neeg nqa khoom
Cov enzymes no ua haujlwm ntawm kev ua kom nrawm hloov cov tshuaj tiv thaiv ntawm cov seem molecular thiab cov pab pawg ua haujlwm. Piv txwv li, phosphofructokinase.
Yim pawg ntawm cov catalysts yog qhov txawv raws li cov pab pawg xa mus. Cia peb saib ob peb leeg xwb.
- Phosphotransferases - pab hloov phosphoric acid residues. Lawv muab faib ua subclasses raws li qhov chaw (cawv, carboxyl thiab lwm yam).
- Aminotransferases - ua kom cov amino acid hloov pauv cov tshuaj tiv thaiv.
- Glycosyltransferases - hloov glycosyl residues los ntawm phosphorus ester molecules rau mono- thiab polysaccharide molecules. Muab cov tshuaj tiv thaivKev tawg thiab kev sib txuas ntawm oligo- lossis polysaccharides hauv cov nroj tsuag thiab tsiaj txhu. Piv txwv li, lawv koom nrog hauv kev tawg ntawm sucrose.
- Acyltransferases hloov carboxylic acid residues rau amines, cawv thiab amino acids. Acyl-coenzyme-A yog ib qho chaw thoob ntiaj teb ntawm acyl pawg. Nws tuaj yeem suav hais tias yog ib pab pawg nquag ntawm acyltransferases. Acetic acid acyl feem ntau zam tau.
Hydrolases - cais nrog dej
Nyob rau hauv pab pawg no, enzymes ua raws li catalysts rau cov kev cuam tshuam ntawm kev sib cais (tsawg dua synthesis) ntawm cov organic tebchaw, uas dej koom nrog. Cov tshuaj ntawm pab pawg no muaj nyob rau hauv cov hlwb thiab hauv cov kua txiv hmab txiv ntoo. Molecules ntawm catalysts nyob rau hauv lub plab zom mov muaj ib tug tivthaiv.
Qhov chaw ntawm cov enzymes no yog lysosomes. Lawv ua cov haujlwm tiv thaiv ntawm cov enzymes hauv lub cell: lawv rhuav tshem cov khoom txawv teb chaws uas tau dhau los ntawm daim nyias nyias. Lawv kuj rhuav tshem cov tshuaj uas tsis xav tau los ntawm lub xovtooj, uas cov lysosomes muaj npe hu ua orderlies.
Lawv lwm "npe" yog kev tua tus kheej ntawm tes, vim lawv yog cov cuab yeej tseem ceeb rau cell autolysis. Yog tias muaj kab mob tshwm sim, cov txheej txheem inflammatory pib, lysosome membrane yuav permeable thiab hydrolases nkag mus rau hauv cytoplasm, rhuav tshem txhua yam hauv nws txoj kev thiab rhuav tshem lub cell.
cais ntau hom catalysts los ntawm pab pawg no:
- esterases - lub luag haujlwm rau hydrolysis ntawm cawv esters;
- glycosidases - ua kom cov hydrolysis ntawm glycosides, nyob ntawmLawv ua li cas isomer ua, zais α- lossis β-glycosidases;
- peptide hydrolases yog lub luag haujlwm rau hydrolysis ntawm peptide daim ntawv cog lus hauv cov protein, thiab nyob rau hauv qee yam kev mob rau lawv cov synthesis, tab sis cov txheej txheem ntawm cov protein synthesis tsis siv nyob rau hauv lub cell nyob;
- amidases - lub luag haujlwm rau hydrolysis ntawm acid amides, piv txwv li, urease catalyzes qhov kev tawg ntawm urea rau hauv ammonia thiab dej.
Isomerases - kev hloov pauv ntawm cov molecule
Cov tshuaj no nrawm hloov pauv hauv ib lub molecule. Lawv tuaj yeem yog geometric lossis qauv. Qhov no tuaj yeem tshwm sim hauv ntau txoj hauv kev:
- hloov ntawm hydrogen atoms;
- txhob pab pawg phosphate;
- hloov kev npaj ntawm pawg atomic hauv qhov chaw;
- txhob ob daim ntawv cog lus.
Isomerization tuaj yeem yog cov organic acids, carbohydrates lossis amino acids. Isomerases tuaj yeem hloov aldehydes rau ketones thiab, hloov pauv, rov kho daim ntawv cis rau daim ntawv trans thiab rov ua dua. Txhawm rau kom nkag siab zoo dua qhov ua haujlwm ntawm cov enzymes ntawm pab pawg no ua haujlwm, nws yuav tsum paub qhov txawv ntawm isomers.
Liass cut ties
Cov enzymes no ua kom tsis muaj hydrolytic tawg ntawm cov organic tebchaw los ntawm daim ntawv cog lus:
- carbon-carbon;
- phosphorus-oxygen;
- carbon-sulphur;
- carbon-nitrogen;
- carbon-oxygen.
Hauv qhov no, cov khoom siv yooj yim xws li carbon dioxide, dej, ammonia raug tso tawm, thiab ob daim ntawv cog lus raug kaw. Ob peb ntawm cov tshuaj tiv thaiv no tuaj yeem mus rau qhov tsis sib xws, cov enzymes sib xws hauv qhov tsim nyogNyob rau hauv cov xwm txheej no catalyze cov txheej txheem tsis tsuas yog lwj, tab sis kuj synthesis.
Liases raug cais raws li hom ntawv cog lus uas lawv tawg. Lawv yog complex enzymes.
Ligase crosslinks
Lub luag haujlwm tseem ceeb ntawm cov enzymes ntawm pab pawg no yog kev ua kom nrawm ntawm kev sib xyaw ua ke. Lawv qhov tshwj xeeb yog kev sib txuas ntawm cov tsim nrog kev lwj ntawm cov khoom uas muaj peev xwm muab lub zog rau kev siv cov txheej txheem biosynthetic. Muaj rau subclasses raws li hom kev sib txuas tsim. Tsib ntawm lawv zoo ib yam rau cov pab pawg lyase, thiab thib rau yog lub luag haujlwm tsim cov ntawv cog lus nitrogen-hlau.
Qee ligases koom nrog hauv cov txheej txheem tseem ceeb ntawm tes. Piv txwv li, DNA ligase koom nrog hauv kev rov ua dua ntawm deoxyribonucleic acid. Nws crosslinks ib leeg-strand so, tsim tshiab phosphodiester bonds. Nws yog nws uas txuas cov Okazaki fragments.
Tib enzyme yog nquag siv hauv kev tsim kho caj ces. Nws tso cai rau cov kws tshawb fawb los txuas ua ke DNA molecules los ntawm cov khoom uas lawv xav tau, tsim cov chains tshwj xeeb ntawm deoxyribonucleic acid. Txhua yam ntaub ntawv tuaj yeem muab tso rau hauv lawv, yog li tsim lub Hoobkas rau kev tsim cov protein tsim nyog. Piv txwv li, koj tuaj yeem xaws rau hauv DNA ntawm cov kab mob ib daim uas yog lub luag haujlwm rau kev sib txuas ntawm insulin. Thiab thaum lub xov tooj ntawm tes yuav txhais nws cov proteins, tib lub sijhawm nws yuav ua rau muaj txiaj ntsig zoo tsim nyog rau kev kho mob. Txhua yam uas tseem tshuav yog los ntxuav nws thiab yuav pab tau ntau tus neeg mob.
Lub luag haujlwm loj ntawm cov enzymes hauv lub cev
Lawv ua taunce cov tshuaj tiv thaiv ntau tshaj kaum zaug. Nws tsuas yog tsim nyog rau kev ua haujlwm ntawm tes. Thiab cov enzymes koom nrog hauv txhua qhov tshuaj tiv thaiv. Yog li ntawd, cov haujlwm ntawm cov enzymes hauv lub cev muaj ntau haiv neeg, zoo li txhua yam kev ua tsis tu ncua. Thiab qhov tsis ua tiav ntawm cov catalysts no ua rau muaj qhov tshwm sim loj.
Enzymes tau dav siv hauv cov zaub mov, kev lag luam teeb, tshuaj: lawv siv los ua cheeses, hnyuv ntxwm, zaub mov kaus poom, thiab yog ib feem ntawm cov hmoov ntxhua. Lawv kuj tau siv rau hauv kev tsim cov khoom siv yees duab.
