Matanho ekufema kwemhepo: Maitiro Akakosha kuhupenyu
Kufema nemhepo (Aerobic respiration) inzira inokosha yemakemikari inoitika mukati memasero ezvisikwa zvipenyu kuti igadzire simba. Iyi nzira chikamu chemetabolism umo okisijeni inoshandiswa kuoxidize mamorekuru eglucose, zvichikonzera simba muchimiro cheadenosine triphosphate (ATP). Kufema nemhepo kwakasiyana nekufema nemhepo isina mweya nekuti kunosanganisira okisijeni uye kunoshanda zvakanyanya mukugadzira simba. Chinyorwa chino chichatsanangura matanho ekufema nemhepo, ane zvikamu zvina zvikuru: glycolysis, oxidative decarboxylation, citric acid cycle (Krebs cycle), uye electron transport chain.
1. Glycolysis: Kutanga kweKuparara kweGlucose
Glycolysis ndiyo nhanho yekutanga yekufema kwe aerobic, inoitika mu cytoplasm yesero. Kunyangwe iri chikamu chekufema kwe aerobic, glycolysis haidi okisijeni uye nekudaro inogona kuitika mumamiriro ese ari maviri e aerobic uye anaerobic. Maitiro aya anoshandura molekyuru imwe yeglucose (ine maatomu matanhatu ekabhoni) kuita mamorekuru maviri e pyruvate (imwe neimwe ine maatomu matatu ekabhoni).
Glycolysis ine zvikamu gumi zvakaoma zve enzyme, asi inogona kukamurwa kuita zvikamu zviviri zvikuru: chikamu chekudyara simba uye chikamu chekudyara simba. Muchikamu chekudyara simba, sero rinoshandisa mamorekuru maviri eATP kuti ritange kuputsika kweglucose. Uyezve, muchikamu chekudyara simba, mamorekuru mana eATP nemamorekuru maviri eNADH anogadzirwa, zvichikonzera kuwedzera kweATP mbiri pamorekuru imwe neimwe yeglucose.
Maitiro makuru anoitika mu glycolysis anosanganisira phosphorylation ye glucose, kupatsanurwa kwe fructose 1,6-bisphosphate kuita mamorekuru maviri e three-carbon, uye oxidation ye triose phosphate kuti ibudise pyruvate. Chibereko chekupedzisira che glycolysis, pyruvate, chinozogadziriswazve mu mitochondria yesero.
2. Kubvisa kabhohaidhiretsi muropa: Kushandurwa kwePyruvate kuita Acetyl CoA
Mushure me glycolysis, mamorekuru maviri e pyruvate anotakurwa kuenda ku mitochondria kune chikamu chechipiri chekufema kwe aerobic, oxidative decarboxylation. Muchikamu chino, morekuru yega yega ye pyruvate inofambiswa ne decarboxylation uye kukura kuti igadzire acetyl CoA (acetyl coenzyme A), iyo inopinda mu citric acid cycle.
Maitiro aya anosanganisira enzyme complex inonzi pyruvate dehydrogenase. Munguva iyi, pyruvate inorasikirwa neatomu imwe chete yekabhoni muchimiro chekabhoni dhayokisaidhi uye inosanganiswa neNAD+, zvichigadzira NADH. Chimwe chinhu chakakosha, boka reacetyl rekabhoni mbiri, rinosanganiswa necoenzyme A kuti rigadzire acetyl CoA.
Kubviswa kwekabhohaidhiretsi mumuviri hakungodi chete pakufema kwemuviri chete asiwo chinhu chakakosha pakugadzirisa mamwe maitiro ekugadzirisa muviri. Chibereko chedanho rino, acetyl-CoA, chinhu chakakosha munzira dzakasiyana dzekugadzirisa muviri, kusanganisira lipid ne ketone biosynthesis.
3. Kutenderera kweCitric Acid: Kugadzira Simba Rinobaya Mwoyo
Danho rechitatu rekufema kwemhepo inonzi citric acid cycle, inozivikanwawo seKrebs cycle kana kuti tricarboxylic acid (TCA) cycle. Maitiro aya anoitika mu mitochondrial matrix uye anosanganisira maitiro akasiyana-siyana anoita kuti acetyl CoA iite carbon dioxide.
Kutenderera uku kunotanga apo acetyl CoA inosangana neoxaloacetate kuti igadzire citrate, iyo inobva yachinja zvakasiyana-siyana, ichigadzira mamorekuru maviri ecarbon dioxide, rimwe ATP (kana GTP), matatu NADH, uye rimwe FADH2 kune rimwe nerimwe acetyl CoA yakasanganiswa. Aya maNADH neFADH2 anobva ashanda sema electron carriers mumatanho anotevera.
Kutenderera kwe citric acid kwakakoshawo pakuvandudzwa kwe oxaloacetate, iyo inoshandiswazve mukufamba uye inopa zvinhu zvakakosha zve biosynthesis ye biomolecules dzakawanda. Kunyangwe huwandu hushoma hweATP huchigadzirwa zvakananga nekufamba uku, NADH neFADH2 zvinogadzirwa zvinoita basa rakakosha mukugadzirwa kwesimba panguva yekufema kwe aerobic.
4. Chiteshi cheKutakura Maerekitironi: Kugadzirwa kweATP Yakanyanya
Danho rekupedzisira rekufema kwemhepo inonzi aerobic kufema ndiro electron transport chain, iyo inoitika mu inner mitochondrial membrane. Danho iri rinosanganisira mapuroteni akawanda anotamisa maerekitironi kubva kuNADH neFADH2 kuenda kuokisijeni, zvichigadzira mvura uye zvichikurumidzisa kugadzirwa kweATP.
Maitiro aya anosanganisira matanho akati wandei akakosha: maerekitironi kubva kuNADH neFADH2 anotakurwa kuburikidza nema enzyme complexes ari mu mitochondrial membrane, akadai sema complexes I-IV. Munguva yekutamiswa uku, mapurotoni anopombwa kubva mu mitochondrial matrix kuenda kunzvimbo yepakati pemembrane, zvichigadzira proton gradient.
Iyi gradient inoshandiswa neATP synthase kugadzira ATP kubva kuADP nephosphate, mukuita kunonzi oxidative phosphorylation. Okisijeni inoshanda seyekupedzisira electron acceptor uye inosangana nemaproton kugadzira mvura. Oxidative phosphorylation ndiyo inonyanya kukonzera kugadzirwa kweATP mukufema kwe aerobic, ine mamorekuru anosvika makumi matatu nemana eATP anogadzirwa pamorekuru imwe neimwe yeglucose.
Mhedziso: Kukosha kwekufema kwemhepo
Kufema kwemhepo nemhepo ndeimwe yenzira dzinonyanya kukosha dzinotungamira hupenyu muzvinhu zvipenyu zvemhepo. Kuburikidza nematanho eglycolysis, oxidative decarboxylation, citric acid cycle, uye electron transport chain, zvipenyu zvinogona kuputsa mamorekuru eglucose kuti zviburitse simba uye zvichengetedze muchimiro cheATP. Maitiro aya akakosha kwete chete kune simba asiwo kune dzimwe nzira dzakawanda dzemetabolism mumuviri.
Kunzwisisa matanho ekufema kwe aerobic kunopa ruzivo rwakadzama pamusoro pekuti masero anoshandisa sei simba uye anotarisira sei zviwanikwa zvawo. Uyezve, kudzidza zvakadzama nezvekufema kwe aerobic kunogonawo kugadzira nzira yekugadzirisa matambudziko akasiyana-siyana ehutano ane chekuita ne metabolism uye simba mumuviri wemunhu. Saka, kufema kwe aerobic hakusi kungori maitiro e biochemical chete, asiwo kiyi yekupona kwedu uye hutano.
