Mehlala ea Lipotso Tse Buisanang ka Potoloho ea Krebs kapa Potoloho ea Citric Acid
Potoloho ea Krebs, e tsejoang hape e le potoloho ea asiti ea citric, ke letoto la lik'hemik'hale tse sebelisoang ke lintho tsohle tse phelang tse nang le aerobic ho hlahisa matla ka ho lokolla acetyl-CoA ho tsoa lik'habohaedreite, mafura le liprotheine. Potoloho ena e etsahala mitochondria 'me ke karolo ea bohlokoa ea ho hema ha sele. Sehloohong sena, re tla tšohla mehlala e amanang le potoloho ea Krebs le litharollo tsa eona ho re thusa ho utloisisa ts'ebetso ena ea bohlokoa hamolemo.
Mehopolo ea Motheo ea Potoloho ea Krebs
Pele re teba bothateng bona, ho bohlokoa ho utloisisa mohopolo oa motheo oa potoloho ea Krebs. E kenyelletsa letoto la liketso tse robeli tse qalang ka motsoako oa acetyl-CoA le oxaloacetate ho theha citrate. Potoloho e ntan'o tsoela pele ka letoto la liketso tse lebisang ho thehoeng ha oxaloacetate, hammoho le ho lokolloa ha carbon dioxide le tlhahiso ea limolek'hule tse nang le matla a mangata joalo ka NADH le FADH2.
Mohlala oa Potso ea 1: Ho Khetholla Lihlahisoa tsa Krebs Cycle
Potso:
Lihlahisoa tsa ho qetela tsa potoloho e le 'ngoe ea potoloho ea Krebs ke life 'me li phetha karolo efe ho phefumoloheng ha sele?
Puisano:
Potolohong e 'ngoe ea potoloho ea Krebs, lihlahisoa tsa ho qetela tse hlahisoang li kenyelletsa:
– Limolek'hule tse 3 tsa NADH
– molek'hule e le 'ngoe ea FADH2
– Molek'hule e le 'ngoe ea ATP (kapa GTP, ho latela sebopuoa)
– limolek'hule tse 2 tsa CO2
Lihlahisoa tsena li bapala karolo ea bohlokoa ho phefumoloheng ha sele. NADH le FADH2 ke limolek'hule tsa lielektrone tse nang le matla a mangata tse sebelisoang ketane ea lielektrone ho hlahisa ATP e ngata ka phosphorylation ea oxidative. Khabone e hlahisoang ke sehlahisoa ke litšila tse ntšoang ka ho phefumoloha.
Mohlala oa Potso ea 2: Tsela ea ho Kena ea Acetyl-CoA
Potso:
Acetyl-CoA e kena joang potolohong ea Krebs, hona acetyl-CoA ena e tsoa hokae?
Puisano:
Acetyl-CoA e kena potolohong ea Krebs ka ho kopanya le oxaloacetate ho theha citrate, e leng mohato oa pele oa potoloho. Acetyl-CoA ka boeona e ka tsoa mehloling e fapaneng, ho kenyeletsoa:
– Ho tlosa oxidative carboxylation ea pyruvate (sehlahisoa sa glycolysis)
- Katabolism ea mafura a acid ka beta-oxidation
- Ho aroloa ha li-amino acid tse itseng
Mohlodi wa acetyl-CoA o itshetlehile ka mofuta wa phepo eo sele e e senyang bakeng sa ditlhoko tsa matla.
Mohlala oa Potso ea 3: Li-enzyme tsa Bohlokoa Potolohong ea Krebs
Potso:
Bolela 'me u hlalose karolo ea li-enzyme tsa bohlokoa tse laolang sekhahla sa potoloho ea Krebs.
Puisano:
Tse ling tsa lienzyme tsa bohlokoa potolohong ea Krebs li kenyelletsa:
1. Citrate Synthase: E susumetsa karabelo ea condensation ea acetyl-CoA le oxaloacetate ho theha citrate. Ena ke mohato oa pele le ntlha ea bohlokoa ea taolo bakeng sa ho kena ha molek'hule potolohong ea Krebs.
2. Isocitrate Dehydrogenase: E thusa ho oxidation ea isocitrate ho alpha-ketoglutarate ha e ntse e lokolla CO2 le ho fokotsa NAD+ ho NADH. Ena ke e 'ngoe ea mehato e laoloang ka ho fetisisa ke allosteria.
3. Alpha-Ketoglutarate Dehydrogenase: E thusa ho fetola alpha-ketoglutarate ho ba succinyl-CoA, hape le ka ho lokolloa ha CO2 le ho thehoa ha NADH.
Li-enzyme tsena li laoloa ka mekhoa ea allosteric 'me li fumaneha ka mefuta ea phosphorylated/dephosphorylated ho latela litlhoko tsa matla tsa sele.
Mohlala oa Potso ea 4: Li-Coenzyme le Li-Cofactor
Potso:
Hlalosa karolo ea li-coenzyme le li-cofactor potolohong ea Krebs.
Puisano:
Li-coenzyme le li-cofactor li bapala karolo ea bohlokoa ho tsoeleng pele ha potoloho ea Krebs. Tse ling tsa tsena li kenyelletsa:
– NAD+ le FAD: E sebetsa e le liamoheli tsa lielektrone tse fokotsoang ho NADH le FADH2, tse thusang ho jara lielektrone ho ea ketaneng ea lipalangoang tsa lielektrone.
– Coenzyme A (CoA): E isa lihlopha tsa acetyl potolohong mme e thusa ho theheng ha succinyl-CoA.
– Li-ion tsa tšepe tse kang Mg2+ le Ca2+: Li sebetsa e le li-cofactor tse hlokahalang bakeng sa ts'ebetso e ntle ea li-enzyme tse 'maloa potolohong.
Mohlala oa Potso ea 5: Tšusumetso ea Potoloho ea Krebs Mafung a Metabolic
Potso:
Ho se sebetse hantle ha potoloho ea Krebs ho ka kenya letsoho joang ho lefu la metabolism?
Puisano:
Ho se sebetse hantle ha potoloho ea Krebs ho ka lebisa maemong a 'maloa a metabolism. Mohlala:
– Liphetoho tse amang li-enzyme tsa potoloho li ka lebisa ho bokellaneng ha lintho tse sa batleheng tse bohareng, e leng se sitisang homeostasis ea sele.
– Mafu a kang fumarase kapa khaello ea alpha-ketoglutarate dehydrogenase a ka baka mefuta e fapaneng ea li-myopathies tsa metabolic tsa mitochondrial.
– Taolo e mpe ea potoloho ea Krebs e ka amahanngoa le mafu a kang mofetše, moo maemo a eketsehileng a isocitrate dehydrogenase e fetotsoeng a hlahisang 2-hydroxyglutarate, e leng oncometabolite e khothalletsang ho hlahala ha hlahala.
Ho koala
Kutloisiso e batsi ea potoloho ea Krebs ke ea bohlokoa bakeng sa tlhahlobo ea metabolism ea sele le bioenergetics. Ka ho utloisisa mehato ea bohlokoa le li-enzyme tse amehang, le kamoo potoloho e kopanang le litsela tse ling tsa metabolism, re ka utloisisa hamolemo fisioloji ea sele le pathophysiology. Ho ithuta mehlala ho ka nolofatsa kutloisiso ea mohopolo ona o rarahaneng oa sele le ts'ebeliso ea oona bophelong bo botle le mafung.
