Krebs voj voog - lub ntsiab theem thiab cuam tshuam rau lom systems

Lub ib thooj ntawm cov pa roj carbon tshuaj zog yog tso tawm nyob rau hauv aerobic tej yam kev mob uas muaj oxygen. Lub Krebs voj voog yog tseem hu ua lub citric acid voj voog, los yog ntawm tes respiration. Nyob rau hauv qhov cim rau ib tug neeg tshua ntawm tus txheej txheem twb tau mus kawm los ntawm ntau zaum: A. Szent-Gyorgyi, A. Lehninger, X. Lub Krebs mus los yog lub npe muab, SE Severin thiab lwm tus neeg.

Ntawm aerobic thiab co neej puas carbohydrates muaj ib tug nyob ze correlative kev sib raug zoo. Ua ntej ntawm tag nrho cov, nws yog qhia nyob rau hauv lub xub ntiag ntawm pyruvic acid, uas yog ua kom tiav cov co zom cov zaub mov ntawm carbohydrates thiab pib cellular ua pa (Krebs voj voog). Ob theem yog tshwmsim los ntawm tib lub enzyme. Cov tshuaj muaj zog tso tawm los ntawm ntsev, yog tseg raws li macroergs ATP. Cov tshuaj tshua muab kev koom tes yog ib yam coenzymes (NAD, NADP) thiab cations. Lub sib txawv yog raws li nram no: yog hais tias co neej puas carbohydrates feem ntau laus nyob rau hauv hyaloplasm, lub cellular pa tshua tshwm sim mas nyob rau hauv mitochondria.

Nyob rau hauv tej yam tej yam kev mob muaj yog ib tug kev thaiv kev nyob nruab nrab ntawm lub ob theem. Yog li, lub xub ntiag ntawm cov pa tshuaj tiv thaiv tus nqi ntawm glycolysis txo sharply (Pasteur nyhuv). glycolysis khoom tej zaum yuav inhibit lub aerobic metabolism ntawm carbohydrates (Crabtree nyhuv).

Lub Krebs voj voog yog ib tug series ntawm tshuaj ua nyob rau hauv lub degradation khoom ntawm carbohydrates yog oxidized rau carbon dioxide thiab dej, thiab tshuaj zog tsim nyob rau hauv lub zog-nplua nuj tebchaw. Thaum lub sij hawm cellular ua pa yog ua "carrier" - oxaloacetic acid (SCHOK). Tom qab hws nrog "carrier" tshuab txais residue acetic acid. Muaj tricarboxylic acid - citric. Thaum lub sij hawm tshuaj haum, muaj yog ib tug "tig" residue nyob rau hauv acetic acid voj voog. Vim hais tias txhua molecule ntawm pyruvic acid yog tsim kaum yim molecules adenozintrifosfatnoy acid. Qhov kawg ntawm lub voj voog nws yog tso tawm "cov cab kuj", uas reacts nrog tshiab molecules tshuab txais residue acetic acid.

Krebs voj voog cov tshuaj tiv thaiv

Yog hais tias qhov kawg khoom ntawm co zom cov zaub mov ntawm carbohydrates yog lactic acid, nyob rau hauv tus ntawm lactate dehydrogenase yog oxidized rau pyruvic acid. Part ntawm lub lwg me me ntawm pyruvic acid yog lub synthesis ntawm "carrier" SCHOK pawg pyruvate carboxylase enzyme nyob rau hauv lub xub ntiag ntawm Mg2 + ions. Part pyruvic acid molecules yog ib qhov chaw ntawm ib tug "active acetate" - atsetilkoenzima A (acetyl-CoA). Cov tshuaj tiv thaiv yog nqa tawm nyob rau hauv tus ntawm pyruvate dehydrogenase. Acetyl-CoA muaj zog daim ntawv cog lus, uas accumulates nyob ib ncig ntawm 5-7% ntawm lub zog. Lub ib thooj tshuaj zog uas ua los ntawm oxidation ntawm "active acetate".

Pawg tsitratsintetazy pib ua tau hauj lwm zoo Krebs voj voog, uas ua rau yus mus rau tsim ntawm citrate acid. Qhov no acid yog tus akonitat hydratase dehydrogenated thiab hloov dua siab tshiab rau hauv lub cis-aconitic acid hais tias tom qab ntxiv ntawm cov dej molecule kis mus rau hauv isocitric. Nruab nrab ntawm lub peb tricarboxylic acids dynamic equilibrium yog tsim los pab.

Isocitric acid yog oxidized rau oxalosuccinic, uas yog decarboxylated thiab hloov dua siab tshiab rau alpha-ketoglutaric acid. Cov tshuaj tiv thaiv yog tshwmsim los ntawm lub enzyme isocitrate. Alpha-ketoglutaric acid nyob rau hauv tus ntawm lub enzyme 2-oxo- (alpha-keto) -glutaratdegidrogenazy decarboxylated, ua nyob rau hauv lub tsim ntawm succinyl-CoA muaj zog daim ntawv cog lus.

Nyob rau hauv lub kauj ruam tom ntej succinyl-CoA los ntawm cov enzyme succinyl-CoA synthetase hau zog daim ntawv cog lus GDF (guanozindifosfatnoy acid). GTP (guanozintrifosfatnaya acid) nyob rau hauv tus ntawm lub enzyme adenylate xa GTP-zog daim ntawv cog lus AMP (adenozinmonofosfatnoy acid). Krebs voj voog: mis - GTP + AMP - GDP + ADP.

Succinic acid nyob rau hauv qhov kev txiav txim ntawm lub enzyme succinate dehydrogenase (LDH) yog oxidized rau fumaric. SDG Coenzyme yog flavin adenine dinucleotide. Fumarate pawg fumaratgidratazy enzyme yog hloov dua siab tshiab rau hauv malic acid, uas nyob rau hauv lem yog oxidized tsim SCHOK. Nyob rau hauv lub xub ntiag ntawm lub reacting system acetyl-CoA SCHOK dua muaj nyob rau hauv lub tricarboxylic acid voj voog.

Yog li, ib tug qauv ntawm cov zib yog tsim rau 38 molecules ntawm ATP (ob - vim co glycolysis, rau - raws li ib tug tshwm sim ntawm oxidation ntawm ob molecules ntawm NAD · H + H +, uas yog tsim nyob rau thaum lub sij hawm glycolytic oksireduktsii thiab 30 - vim TCA). CTLs efficiency ntawm 0.5. Tus so ntawm lub zog yog dissipated li thaum tshav kub kub. Lub TCA yog oxidized 16-33% lactate acid, tus so ntawm nws loj yog nyob rau hauv lub resynthesis ntawm glycogen.