Electron Transport Chain

• Proton motive force would go back to the matrix and that would lead to the phosphorylation of ADP to ATP
• The complete oxidation of glucose with 6O2 produces CO2 and 6 H2O
• The complete oxidation of glucose is broken down to 2 half reactions: Glucose is hydrolyzed with 6H2O to form 6 CO2, 24 H+ and 24 e-
• The first step during the electron transport process is where NADH and FADH2 are reoxidized to NAD+ and FAD
• The second reaction during the electron transport process is where the transferred electrons participate in the sequential oxidation reduction of multiple redox centers in four enzyme complexes before reducing O2 to H2O
• The third reaction in the electron transport chain is where during electron transfer, the protein are expelled from the mitochondrion, producing a proton gradient across the mitochondrial membrane
• The site of ETC and oxidative phosphorylation occurs in the mitochondria
• Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH2 to O2, by a series of electron carriers
• The mitochondria has a inner and a outer membrane. The inner membrane is made of protein which separates from the outer membrane
• The cristae are folds within the inner membrane that increase surface area for respiration
• The matrix is a gel like substance which contains most of the enzymes, metabolites involved in the citric acid cycle and fatty acid beta oxidation
• Mitochondrial cristae prevents migration of metabolites across the inner mitochondrial membrane
• Ions and metabolites enter mitochondria by transporters. The intermembrane space is equivalent to the cytosol in its concentration of metabolites and ions
• The NADH allow movement across the mitochondrial membranes]
• Cytosolic reducing equivalents and not oxaloacetate are transported to the mitochondria
• The complete oxidation of glucose move electrons from cytoplasmic NADH, derived from glycolysis, into the mitochondrial ETC
• The glycerophosphate shuttle resulted to 1.5 ATP per molecule of FADH2.
• The entry of ADP into mitochondria is coupled to the exit of ATP by ATP-ADP Translocase is through ADP^3- cytoplasm + ATP^4- matrix -> ADP^3-matrix + ATP^4 cytoplasm
• BOVINE ATP-ADP translocator is a dimer, and has 1 binding site to the nucleotides and it both binds ATP and ADP competitively
• The bovine ATP-ADP translocator protons bind across the ATP
• The ADP-ATP translocase catalyzes the coupled entry of ADP and exit of ATP
• In the binding of ADP, from the cytoplasm favors eversion of the transporter. To release the ADP from the matrix..
• The phosphate must be imported into the mitochondrion
• The free energy of electron transport from NADH to O2 can proceed the synthesis of approximately 2.5 ATP. Water soluble or the outer membrane can absorb electrons
• The oxidation of NADH and FADH2 is carried out by the affinity of electrons in the ETC. A set of protein complexes containing redox centers with progressively greater affinities for electrons
• The respiratory chain consists of four complexes: Three proton pumps and a physical link to the citric acid cycle
• The NADH is oxidized to NADH Q Oxidoreductase; Ubiquinone (Q), and succinate Q reductase as the collector point to form Q Cytochrome c oxidoreductase. Next would be the water soluble Cyt C collector point would be converted to Cytohrome c oxidase which then converts to water
• NADH Q oxidorreductase would oxidize NADH and shuttles to coenzyme Q
• Succinate Q reductase transports its electrons to Q forming Q-Cytochrome c oxidoreductase
• Cytochrome c oxidoreductase transfers electrons to cytochrome c
• Cytochrome c oxidase transfers electrons to oxygen
• Antimycin A inhibits complex III
• Rotenone or Amytal inhibits complex 1. Which produces less ATP than antimycin A
• FMN serves as a redox center due to high high reduction potential
• Electron carriers are arranged in the mitochondrial membrane so that electrons travel from complexes 1 and II, and passed to Complex III by coenzyme Q, and from there to Complex IV by cytochrome C
• Complex I, III, and IV pumps protons in the intermembrane space
• In complex II, FADH2 collects the electrons to coenzyme Q
• Coenzyme Q is a hydrophobic
• Ubiquinone to Ubiquinol via reduction
• Complex I transports electrons NADH to coenzyme Q.