Question

Explain the chemiosmotic mechanism of ATP generation. How does oxidative phosphorylation compare with substrate level phosphorylation found in glycolysis and the Kreb’s cycle?

Answer 1

all an potential CHEMI-OSMOTIC THEORY: - The coupling, of oxidation with phosphorylation is tormed oxidative phosphorylation The ial membrane is accom tompost of footons from inside to odside of inner mitochonda- panied by the generation of a proton gradient across the membrane. Pootone (21+ Cons) 'accumulate outside the membrane a creating. electrochemical difference. This pooton motivé force drives the synthesis of ATP by ATP synthase complex $ Electron Younspost chain The electron floco occurs through Successive dehydrogenase enzymes , togethez Janown as electron transport chain (ETC) . The electron flow from electronegative potential (-0.32) to electroposibue "potential (+0.82). → ETC complex d ww. It is also called NTADH-Col reductase or dehydrogenase complex 57 is tightly bound to the inner membrane CIW). It contains a flavoprotein (Fp), consisting of Fant as prosthetic group and an ioon- sulphur prolin (Fc-s). NADH is the donor of electrons , FMN accepts them and gets reduced to FMNHZ". Two electrons and one hydrogen Ion are transforred from NADH to the flavin prosthetic group NADH A of mitochondria of the enzyme.

NADH and the out of FAD>Fes-> (002- NADH +++ FMN FMNIH2 +NAPT. The electrons from Fmote are then transfoured to lë-s. the electrone more then toens forred to coenzyme Q? (ubi quậnone) (60) iv) Overall function of this complex is to colled the pair of elections from pass them to coo. The there is a large negative free enougy change enogy rieleased is 12 kcal (mols Thie id utilized to doivé 4 pro tons the mitochondria Complex I: NADA PMN - Pesa.com 2. Complex I or Succinate_Q-Redaclase – The reaction in complex -II Pe Hepresenteert :- Complex IISuccinate the elections from FADHE' enter the ETC at the level of Csereymell. this step does not liberate enough energy to act as other words, substrates oxidized by Fa blinked encymes bypass proton pump complex I 3. Coenzyme Q She ubiquinone (Q) ls reduced successively to semiquinone (1) and finally to quinol (QH2) It accepté a pair of electron from NJADX OY FAD-n, though complex ior complex -r ' respectively 4. Complet II of Cytocheme Reducese o this le a castor of Pron-sulphur proteina y cytochrome b and aj tochrome Cty both Lonkin' heme boosthetic group Seque 0 Deoring process of twns for of electron, the own in home 3+ and Fe 2+ shetla betiseca Fe group forms! the face cenogy ehange la – bokcal (mol and 4 protons Complex II : Com ---F¢8> cytb-cytas -scytas 6. Cytochrome poripheral membrane protein contain home prosthetic group. Cytochrome c. collebis elecbooms-poñe Comple I and ddives them to tomplex Tv the this CNG pimped out! It is a Onc

a 3 molecular oxygen are r causes 6.Ocomplex 12.oo Cytocheme Oridase – It contaîne chifforent proteins, including cytochrome and Gytochrome o fowe elecloons are acopted from cylochurme c and passed on to 41+ + O2 + 4 Cyt-Fett 23120 + 4 cytettu * 2 prolons pumped out to the inter membrane space. m. Cytochowme oxidase has netox centers namely, 9,937 CuA and Cub. The clectoon Loansfer in this complex is as: - cyto at 6-> CuA > Cylon > Cyto 43 → CulB complex ij : Cykc- cyta-az--02 ->PROTONT Pump AND ATP SYNTHESIS - The proton pumpe (complexes 1, IT, and 11) expel 14+ from inside to outside of thiet in nou membrane · so, there is high Hi concentration outside the inner membrane This causes set to enter into mitochondria through the channels (FO); this.proton influx ATP synthesis by ATP synthase A. silci 4 protons pumped out Mitochondrial Intermembrane Completi space Complex Coo Fes-Cytbncgtcm TEMNfest Innor membran Maloix FADE (8. Sucanate g. Acyl-CoA & Isoiltaate X 10. Gdy carol-3- phosphate 1 Lepoate 6. Pyruvale 7. Nupha keloglutarale components and sequence of rackone of ETC. ATP synthase (complex) - It is a protein assembly in the Enhor mitochondrial membrana H has twoo functional units, named as Fjand Fo Co Gerwise called Fs-FO ATPase) · 37 embedded to looks like Lollipop since the membrane component and 'Ft are connected by a pootan stalk. Site 2 tproton sites 2 proton pumped out pumpedocet Comples > complex Tres NADT 4/202 HZO • Glyceraldekyle-3- phosphate 8. Malate 4. Gleotamate 5. Beta Hydroxy FACFAD) acyl coa 1

The transfer of electrons from the this Oxidative phoe thorylatten Teduced coenzymes through the respiratory chain to oxygen le known as biological oxidation Energy released during is called oxidative proa phony letfon." In the body totie ovdation oliday This couplîng of oxidation with phosphorylation is carried out by successiva steps of dehydrogenatiombat Glycolygls Glycoraldehyde-3-phosphate Ony coraldehyde –3ploephatc< daydrogenase . s 13-bio- is trapped process NAP NADHAHA Phospho-glyce- rate. #Icoatrale dehyelogenase .. Kerb's Cycle :-0 Isocitrate > Oxalo-succnate NAD + NADH+H+ # Alphe Ketoglutaratáchydãogenase O Aysha Ketoglutarale NADT Sonstco. Succiny LOA NADH+H+ Siccinate Succincte dehydrogenase Tumarate AAD Malate dehydrogenas > Oxaloacetate FADIT 2 Malate NAD+ NADH+H+ > when energy is trapped by oudatton of reducing, equivalents such NADH and FADH2 , it is called oxidative phosphorylation q8 J NADH 2.5 ATP I FADH2 = 1,5 ATP