Krebs sake zagayowar - babban saukarwa da kuma abubuwan da nazarin halittu da tsarin

The girma na carbon sinadaran makamashi da aka saki a karkashin aerobic yanayi shafe oxygen. A Krebs sake zagayowar kuma ake kira citric acid sake zagayowar, ko cell numfasawa. A bidiyon dikodi mutum halayen da aiwatar da aka samu halartar masana kimiyya da dama: A. Szent-Gyorgyi, A. Lehninger, X. A Krebs sake zagayowar ne sunan da aka ba, SE Severin da sauransu.

Tsakanin aerobic da anaerobic rugujewar carbohydrates akwai wani kusa correlative dangantaka. Da farko, shi ne aka bayyana a gaban pyruvic acid, wanda aka kammala cikin anaerobic narkewa daga carbohydrates da kuma fara salula numfasawa (Krebs sake zagayowar). Dukansu manzilõli, an catalyzed da wannan enzyme. A sunadarai makamashi sake ta phosphorylation, aka ajiye a matsayin macroergs ATP. A sinadaran halayen da hannu ne guda coenzymes (nad, NADP) da kuma cations. Da bambance-bambance ne kamar haka: idan anaerobic rugujewar carbohydrates yawanci sarrafa a hyaloplasm, da salula numfasawa halayen faruwa yafi a mitochondria.

A karkashin wani yanayi akwai wani abotar tsakanin biyu bulan. Kamar wancan ne, gaban oxygen dauki kudi na glycolysis rage-rage sharply (Pasteur sakamako). glycolysis kayayyakin iya hana aerobic metabolism na carbohydrates (Crabtree sakamako).

A Krebs sake zagayowar ne jerin sunadarai halayen sakamakon a cikin ƙasƙanci kayayyakin na carbohydrates suna oxidized zuwa carbon dioxide da water, da kuma sinadaran da makamashi tara a cikin makamashi-m mahadi. A lokacin salula numfasawa da aka samar "m" - oxaloacetic acid (SCHOK). Daga bisani sandaro da "m" kunna saura acetic acid. Akwai tricarboxylic acid - citric. A lokacin sinadaran halayen, akwai wani "nuna" saura a acetic acid sake zagayowar. Saboda kowane kwayoyin na pyruvic acid da aka kafa su goma sha takwas kwayoyin adenozintrifosfatnoy acid. A ƙarshen sake zagayowar shi ne saki "m", wanda reacts tare da sabon kwayoyin kunna saura acetic acid.

Krebs sake zagayowar dauki

Idan karshen samfurin na anaerobic narkewa na carbohydrates ne lactic acid, a ƙarƙashin rinjayar lactate dehydrogenase aka oxidized zuwa pyruvic acid. Sashe na daga cikin kwayoyin na pyruvic acid ne da kira na "m" SCHOK rinjayi pyruvate carboxylase enzyme a gaban Mg2 + ions. Part pyruvic acid kwayoyin ne tushen wani "aiki acetate" - atsetilkoenzima A (acetyl-CoA). A dauki yana da za'ayi a ƙarƙashin rinjayar pyruvate dehydrogenase. Acetyl-CoA ƙunshi makamashi bond, wanda accumulates a kusa da 5-7% na makamashi. The girma sinadaran makamashi samar da hadawan abu da iskar shaka na "aiki acetate".

Rinjayi tsitratsintetazy fara aiki sosai Krebs sake zagayowar, wadda take kaiwa ga samuwar citrate acid. Wannan acid ne ya rinjayi akonitat hydratase dehydrogenated da kuma tuba a cikin CIS-aconitic acid cewa bayan Bugu da kari daga cikin ruwa kwayoyin wuce zuwa isocitric. Tsakanin uku tricarboxylic acid tsauri ma'auni ne aka kafa.

Isocitric acid da aka oxidized zuwa oxalosuccinic, wanda aka decarboxylated da kuma tuba zuwa ga alpha-ketoglutaric acid. A dauki aka catalyzed da enzyme isocitrate. Alpha-ketoglutaric acid a ƙarƙashin rinjayar da enzyme 2-oxo- (alpha-keto) -glutaratdegidrogenazy decarboxylated, sakamakon samuwar succinyl-CoA hada da makamashi bond.

A mataki na gaba succinyl-CoA da enzyme succinyl-CoA synthetase watsa makamashi bond GDF (guanozindifosfatnoy acid). GTP (guanozintrifosfatnaya acid) a ƙarƙashin rinjayar da enzyme adenylate aika GTP-makamashi bond HAU (adenozinmonofosfatnoy acid). Krebs da'ira: dabara - GTP + HAU - GDP + ADP.

Succinic acid karkashin mataki na enzyme succinate dehydrogenase (LDH) aka oxidized zuwa fumaric. SDG coenzyme aka flavin adenine dinucleotide. Fumarate rinjayi fumaratgidratazy enzyme ne tuba zuwa cikin malic acid, wanda bi da bi ne oxidized ta samar da SCHOK. A gaban da maida martani tsarin acetyl-CoA SCHOK sake kunshe a cikin tricarboxylic acid sake zagayowar.

Saboda haka, wanda kwayoyin na glucose da aka kafa don ya 38 kwayoyin na ATP (biyu - saboda anaerobic glycolysis, shida - a sakamakon hadawan abu da iskar shaka na biyu kwayoyin na nad · H + H +, wanda aka kafa a lokacin glycolytic oksireduktsii da kuma 30 - saboda TCA). CTLs yadda ya dace da 0.5. Sauran makamashi ne dissipated kamar yadda zafi. A TCA aka oxidized 16-33% lactate acid, da sauran ta taro ne a cikin resynthesis na glycogen.