Sau kom tiav oxidation ntawm qabzib. glucose oxidation cov tshuaj tiv thaiv

Qhov tsab xov xwm yuav saib yuav ua li cas lub oxidation ntawm qabzib. Carbohydrates yog poligidroksikarbonilnogo hom tebchaw, thiab derivatives thereof. Cov yam ntxwv nta - lub xub ntiag ntawm aldehyde los yog ketone pab pawg thiab tsawg kawg yog ob hydroxyl pawg.

Nyob rau hauv nws cov qauv, carbohydrates raug muab faib ua monosaccharides, polysaccharides, oligosaccharides.

monosaccharides

Monosaccharides yog qhov nyuaj carbohydrates, uas muaj peev xwm tsis raug hydrolysis. Nyob ntawm seb uas pab pawg neeg yog tam sim no nyob rau hauv muaj pes tsawg leeg - cov aldehyde los yog ketone yog cais aldose (no muaj xws li galactose, qabzib, ribose) thiab ketoses (ribulose, fructose).

oligosaccharides

Oligosaccharides yog carbohydrates uas muaj li ntawm ob mus rau kaum monosaccharide keeb kwm residues koom los ntawm glycosidic linkages. Nyob rau hauv lub xov tooj ntawm monosaccharide residues paub qhov txawv disaccharides, trisaccharides, thiab hais txog. Uas yog tsim los ntawm cov oxidation uas piam thaj? Qhov no yuav tsum tau tham tom qab.

polysaccharides

Polysaccharides yog carbohydrates uas muaj ntau tshaj li kaum monosaccharide units koom ua ke los ntawm glycosidic bonds. Yog hais tias muaj pes tsawg leeg ntawm lub polysaccharide muaj tib lub monosaccharide residues, nws yog hu ua gomopolisaharidom (eg, starch). Yog hais tias cov seem yog cov sib txawv - lub heteropolysaccharide (xws li heparin).

Yuav ua li cas ib qho tseem ceeb yog cov oxidation ntawm zib?

Lub zog ntawm carbohydrates nyob rau hauv tib neeg lub cev

Carbohydrates muaj cov nram qab yam ntxwv tseem ceeb:

1. Zog. Lub ntsiab muaj nuj nqi ntawm carbohydrates, raws li lawv yog lub ntsiab qhov chaw ntawm lub zog nyob rau hauv lub cev. Raws li ib tug tshwm sim ntawm oxidation txaus siab ntau tshaj ib nrab ntawm lub zog xav tau kev pab ntawm tus neeg. Cov oxidation ntawm ib tug gram ntawm cov carbohydrate tso 16.9 kJ.
2. Reserve. Glycogen thiab cov hmoov txhuv nplej yog cia hauv daim ntawv ntawm cov as-ham.
3. Qauv. Cellulose thiab ib co lwm yam polysaccharide tebchaw tsim check cev pob txha nyob rau hauv cov nroj tsuag. Lawv kuj, nyob rau hauv ib tug complex nrog lipids thiab cov proteins uas yog ib feem ntawm cell biomembranes.
4. Tiv. Rau acidic heteropolysaccharides nyob rau hauv lub luag hauj lwm ntawm lom lubricant. Lawv kab nplaim cov pob qij txha, uas yog nyob rau hauv kev sib cuag thiab tshiav tiv thaiv txhua lwm yam, qhov ntswg mucosa, digestive ib ntsuj av.
5. Antigoagulyantnaya. Qhov no carbohydrate yog heparin, muaj ib qho tseem ceeb lom zog - namely, tiv thaiv cov ntshav txhaws.
6. Carbohydrates sawv cev rau ib tug carbon qhov chaw rau lub synthesis ntawm cov nqaijrog, lipids thiab nucleic acids.

Rau kab yog qhov tseem ceeb ntawm carbohydrates, kev noj haus carbohydrates - qab zib, starch, piam thaj, lactose). Qabzib yuav tsim nyob rau hauv lub cev los ntawm cov amino acids, glycerol, lactate thiab pyruvate (gluconeogenesis).

glycolysis

Glycolysis nruab nrab yog ib tug ntawm peb tau ntaub ntawv ntawm cov piam thaj oxidation txheej txheem. Nyob rau hauv tus txheej txheem no lub zog qee khaws tseg los ntawm tom qab ATP thiab NADH. Ib qho ntawm nws molecule splits rau hauv ob molecules ntawm pyruvate.

glycolysis txheej txheem yuav siv sij hawm qhov chaw nyob rau hauv tus ntawm ntau yam enzymatic agents, i.e. catalysts lom xwm. Qhov tseem ceeb tshaj oxidant yog cov pa, tab sis nws yog tsim nyog sau cia hais tias tus txheej txheem ntawm glycolysis yuav tsum tau nyob rau hauv lub qhaj ntawv ntawm cov pa. Qhov no hom ntawm glycolysis co yog hu ua.

Glycolysis yog ib co txheej txheem stepwise oxidation ntawm qabzib. Nrog rau qhov no glycolysis zib oxidation yog ua tsis tiav. Yog li, nyob rau hauv lub oxidation ntawm zib ua tsuas yog ib qho molecule ntawm pyruvate. Ntawm tus taw tes ntawm view ntawm lub zog pab glycolysis co yog tsawg paaj tshaj aerobic. Txawm li cas los, yog hais tias tus cell mus oxygen, cov conversion zaum yuav tshwm sim nyob rau hauv lub aerobic co glycolysis, uas yog lub teb oxidation ntawm qabzib.

Lub mechanism ntawm glycolysis

Nyob rau hauv tus txheej txheem ntawm glycolysis nws decays rau-carbon zib mus rau hauv ob peb carbon molecules ntawm pyruvate. Tag nrho cov txheej txheem yog muab faib ua tsib npaj theem thiab tsib, thaum lub sij hawm uas lub zog yog nyob rau hauv ATP.

Yog li, glycolysis tshwm sim nyob rau hauv ob ua sawv, txhua tus uas yog muab faib ua tsib theem.

Kauj ruam №1 zib oxidation

• Thawj theem. Thaum tus thawj kauj ruam yog cov ntsev ntawm qabzib. Kom ntawm saccharide fosfolirirovaniya tshwm sim los ntawm lub thib rau cov pa roj carbon atom.
• Qhov thib ob theem. Ib tug txheej txheem ntawm isomerization ntawm glucose-6-phosphate. Rau ntawm no theem, qabzib yog twv rau hauv fructose-6-phosphate los ntawm lub catalytic kev txiav txim ntawm phosphoglucoisomerase.
• Qhov thib peb theem. Ntsev ntawm fructose-6-phosphate. Rau ntawm no theem, tus tsim ntawm fructose 1,6-bisphosphate (kuj hu ua aldolase) nyob rau hauv tus ntawm phosphofructokinase-1. Nws yog kev koom tes nyob rau hauv lub accompaniment ntawm ib tug phosphoryl pab pawg neeg los ntawm adenosine triphosphate mus rau ib tug fructose molecule.
• Qhov thib plaub theem. Rau ntawm no theem, cov aldolase cleavage. Raws li ib tug tshwm sim ob triose phosphate molecules, thiab nyob rau hauv particular ketose eldozy.
• Lub tsib theem. Triose phosphate isomerization. Rau ntawm no theem, cov xa glyceraldehyde-3-phosphate nyob rau hauv cov kauj ruam ntawm splitting qabzib. Thaum zoo li no txoj kev hloov tshwm sim dihydroxyacetone phosphate nyob rau hauv daim ntawv ntawm cov glyceraldehyde-3-phosphate. Qhov no txoj kev hloov yog accomplished los ntawm cov kev txiav txim ntawm enzymes.
• Qhov thib rau theem. Cov oxidation ntawm glyceraldehyde-3-phosphate. Rau ntawm no theem, cov oxidation ntawm lub molecule thiab nws cov tom ntej ntsev rau 1,3-diphosphoglycerate.
• Lub xya theem. Qhov no theem yuav cov kev hloov ntawm lub 1,3-diphosphoglycerate phosphate pab pawg neeg kom ADP. Qhov kawg ntawm cov kauj ruam no yog tsim rau hauv 3 lub phosphoglycerate thiab ATP.

Theem №2 - tag oxidation ntawm zib

• Lub yim nyob ntev. Rau ntawm no theem, txoj kev hloov 3-phosphoglycerate 2-phosphoglycerate. Cov kev hloov txheej txheem yog ua nyob rau hauv qhov kev txiav txim ntawm ib qho enzyme xws li phosphoglycerate mutase. Qhov no Science News for KIDS zib oxidation cov tshuaj tiv thaiv hais nrog lub yuav tsum tau muaj ntawm magnesium (Mg).
• Cuaj theem. Rau ntawm no theem, cov lub cev qhuav dej ntawm 2-phosphoglycerate.
• Lub kaum theem. Nyob rau cov kev hloov ntawm phosphate derived ntawm yav dhau los theem ntws nyob rau hauv PEP thiab ADP. Siv los ntawm hloov lwm lub tsev rau ADP fosfoenulpirovata. Xws li ib tug tshuaj cov tshuaj tiv thaiv yog tau nyob rau hauv lub xub ntiag ntawm magnesium ions (Mg) thiab poov tshuaj (K).

Nyob rau hauv aerobic tej yam kev mob, cov txheej txheem los mus CO ₂ thiab H ₂ O. kab zauv ntawm zib oxidation raws li nram no:

C ₆ H ₁₂ O ₆ + 6SO 6D ₂ → ₂ + 6H ₂ O + 2880 kJ / tus nas.

Yog li, lub cell txuam nrog ntawm NADH tshwm sim nyob rau hauv lub tsim ntawm lactate los ntawm qabzib. Qhov no txhais tau tias li ib tug txheej txheem yog ib co, thiab tej zaum nws yuav mus nyob rau hauv lub qhaj ntawv ntawm cov pa. Uas cov pa - kawg electron acceptor, uas yog kis tau NADH nyob rau hauv lub ua pa saw.

Nyob rau hauv tus txheej txheem ntawm xam lub zog tshuav nyiaj li cas ntawm cov glycolytic tshua yuav tsum tau to taub hais tias txhua theem ntawm lub kauj ruam thib ob yog pheej rov qab ua ob zaug. Los ntawm no peb yuav xaus uas nyob rau hauv thawj kauj ruam ob ATP molecules yog siv, thiab thaum lub sij hawm khiav ntawm lub thib ob theem, ib tug 4 ATP-ntsev ntawm ib tug substrate molecule los ntawm hom. Qhov no txhais tau tias li ib tug tshwm sim ntawm oxidation ntawm txhua molecule ntawm zib hlwb noog ob ATP molecules.

Peb tau soj ntsuam cov oxidation ntawm zib los ntawm cov pa.

Co chaw ntawm qab zib oxidation

Aerobic oxidation hu ua oxidation txheej txheem nyob rau hauv uas lub zog xaiv tshwm sim thiab hais tias tshwm sim nyob rau hauv lub xub ntiag ntawm oxygen, cov projecting kawg hydrogen acceptor nyob rau hauv lub ua pa saw. Hydrogen pub molecules protrudes txo daim ntawv coenzymes (FADN2, NADH, NADPH) uas yog tsim los ntawm cov tshuaj tiv thaiv ntawm lub intermediate substrate oxidation.

Tus txheej txheem ntawm aerobic oxidation ntawm zib dichotomic hom yog lub ntsiab txoj kev piam thaj catabolism nyob rau hauv tib neeg. Qhov no hom ntawm glycolysis yuav tsum tau nyob rau hauv tag nrho cov ntaub so ntswg thiab kabmob ntawm tus tib neeg lub cev. Cov tshwm sim ntawm cov tshuaj tiv thaiv yog qhov cleavage ntawm ib tug qauv ntawm cov zib dej thiab carbon dioxide. Lub zog tso nyob rau hauv cov ntaub ntawv no yuav tsum sau nyob rau hauv ATP. Qhov no txoj kev muaj peev xwm yuav muab faib ua peb theem:

1. Tus txheej txheem ntawm hloov dua siab tshiab ntawm zib molecules mus rau hauv ib tug khub ntawm molecules ntawm pyruvic acid. Cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw nyob rau hauv lub cell cytoplasm thiab yog ib txog kev txoj kev cov zib decomposition.
2. Tus txheej txheem ntawm tsim ntawm acetyl-CoA nyob rau hauv lub oxidative decarboxylation ntawm pyruvic acid. Qhov no cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw nyob rau hauv lub cell mitochondria.
3. Cov oxidation ntawm acetyl-CoA mus rau hauv lub Krebs voj voog. Cov tshuaj tiv thaiv yuav siv sij hawm qhov chaw nyob rau hauv lub cell mitochondria.

Nyob rau txhua theem ntawm txoj kev no ua rau cov txo ntaub ntawv ntawm coenzymes, los ntawm oxidizing enzyme ceg ntawm lub pa saw. Qhov no ua ATP los ntawm oxidation ntawm qabzib.

Kev Kawm Ntawv coenzymes

Coenzymes uas yog tsim nyob rau hauv lub thib ob thiab thib peb kauj ruam ntawm aerobic glycolysis, yog oxidized ncaj qha nyob rau hauv lub cell mitochondria. Parallel rau qhov no, NADH, uas yog tsim nyob rau hauv lub cytoplasm ntawm lub cell thaum lub sij hawm cov tshuaj tiv thaiv ntawm tus thawj theem ntawm aerobic glycolysis, muaj tsis muaj peev xwm txeem los ntawm cov mitochondrial membrane. Hydrogen yog kis los ntawm NADH mus rau lub cell cytoplasmic mitochondria los ntawm shuttle mus. Cov no mus yuav qhov txawv cov ntsiab - malate-aspartate.

Tom qab ntawd, lub cytoplasmic NADH tshwm sim nyob rau hauv lub restoration oxaloacetate malate uas nyob rau hauv lem, nkag mus rau lub cell mitochondria thiab ces oxidized los ntawm yuav txo tau ntawm mitochondrial NAD. Oxaloacetate rov mus rau lub cytoplasm nyob rau hauv daim ntawv ntawm cov aspartate.

Mutated ntaub ntawv ntawm glycolysis

Cov kev kawm ntawm glycolysis yuav ntxiv tau nrog los ntawm kev tso cai ntawm 1.3 thiab 2.3-bifosfoglitseratov. Yog li 2,3-bifosfoglitserat nyob rau hauv tus ntawm lub lom catalyst yuav siv mus rau lub glycolysis txheej txheem, thiab ces hloov nws zoo rau lub 3-phosphoglycerate. Cov enzymes ua si ntau yam ntawm lub luag hauj lwm. Piv txwv li, 2,3-bifosfoglitserat nyob rau hauv hemoglobin, yeej txhawb txoj kev hloov ntawm oxygen mus rau cov ntaub so ntswg, yog li pab rau yuav txo tau thiab dissociation ntawm oxygen affinity thiab erythrocytes.

xaus

Muaj ntau cov kab mob muaj peev xwm hloov lub chav kawm ntawm glycolysis daim ntawv rau nws cov ntau theem. Nws yog ua tau los txo lawv tag nrho cov nyiaj los yog kev hloov kho ntawm cov theem ntawm tej yam ntawm ntau yam enzyme tebchaw. Ib txhia ntawm co kab mob muaj peev xwm mus rau lwm cov carbohydrates decomposition txoj kev. Feem ntau ntawm thermophiles muaj tsuas yog ob tug ntawm cov glycolysis enzyme, nyob rau hauv particular, enolase thiab pyruvate kinase.

Peb ntsia li cas hais oxidation ntawm zib nyob rau hauv lub cev.