ELECTRON TRANSPORT CHAIN ' ETS '

ELECTRON TRANSPORT CHAIN IN MITOCHONDRIA

1. CENTRAL UNIVERSITY OF SOUTH BIHAR Name –SUNIL KUMAR SAHOO MSc life science

2. CONTENT Mitochondria Most energy from redox Electron transport chain Complexes 1, 2,3 and 4 Generation of ATP Conclusion Reference

3. MITOCHONDRIA Outer membrane relatively permeable Inner membrane permeable only to those things with specific transporters. -impermeable to NADH and FADH₂ -permeable to pyruvate Compartmentalization -kreb’s and B-oxidation in matrix -glycolysis in cytosol

4. MOST ENERGY FROM REDOX Electrons during metabolic reactions sent to NAD and FAD glycolysis In cytosol Produces 2 NADH -Pyruvate dehydrogenase reaction In mitochondria matrix 6NADH and 2 FADH₂ / GLUCOSE

5. ELECTRON TRANSPORT CHAIN Groups of redox proteins -On inner mitochondria membrane -Binding sites for NADH and FADH On matrix side of membrane Electron transferred to redox proteins NADH Reoxidised to NAD⁺ FADH₂ Reoxidised to FAD

6. 4 COMPLEXES Proteins in specific order Transfer 2 electrons in specific order -proteins localized in complexes Embedded in membrane Ease of electron transfer -Electrons ultimately reduce oxygen to water 2H + +2e⁻ + ½O2→H₂O

7. COMPLEX 1 Has NADH binding site -NADH reductase activity NADH → NAD⁺ - NADH→ FMN→FeS→ Ubiquinone (coenzymeQ) -Ubiquinone→ Ubiquinone H₂ -4H⁺ pumped / NADH EC:1.6.5.3 1 -- Oxidoreductases   1.6 -- Acting on NADH or NADPH   1.6.5 -- With a quinone or similar compound as acceptor

8. COMPLEX 2 Succinate →FAD→Ubiquinone -contains coenzyme Q -FADH₂ binding site FAD reductase activity FADH₂→FAD EC:1.35.1   1 -- Oxidoreductases   1.3 -- Acting on the CH-CH group of donors   1.3.5 -- With a quinone or related compound as acc eptor

9. COMPLEX 3 Ubiquinone → Ubiquinone While cyt C gets reduced Also contains cytochromes bc₁ complex -proton pump 4H⁺ Adds to gradient 8H⁺ / NADH 4H⁺ / FADH₂ EC:1.10.2.2   1 -- Oxidoreductases     1.10 -- Acting on diphenols and related substances as donors    1.10.2 -- With a cytochrome as acceptor

10. COMPLEX 4 Reduction of oxygen Cytochrome -c oxidase Cyt a⁺a3 red→ oxidized state Oxygen → water -2 H⁺ + 2e⁻ + ½ O₂→2 H₂O -Transfers e⁻ one at a time to oxygen Pump 2H⁺ out -Total of 10 H⁺ / NADH -Total of 6 H⁺ / FADH₂ EC:1.9.3.1   1 -- Oxidoreductases     1.9 -- Acting on a heme group of donors     1.9.3 -- With oxygen as acceptor

11. GENERATION OF ATP Proton dependent ATP Synthetase - uses proton gradient to make ATP -Protons pumped through channel on enzyme From intermembrane space into matrix 4H⁺ / ATP Called chemiosmotic theory

12. CONCLUSION

13. REFERENCE Lehninger Principles of Biochemistry  Wikipedia  pathfinder life science book www.chem.qmul.ac.uk/iubmb https://www.expasy.org/