Download - Electron Transport Chain
![Page 1: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/1.jpg)
Electron Transport Chain
![Page 2: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/2.jpg)
Electron Transport Chain
![Page 3: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/3.jpg)
Mitochondrial Structure
![Page 4: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/4.jpg)
Electron Transport Chain Overview
The ETC removes energy stored in the NADH and FADH2 molecules to:
1. create a proton gradient across the inner mitochondrial membrane
2. convert O2 to H2O.
All reactions are redox reactions.
![Page 6: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/6.jpg)
ETC Components
![Page 7: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/7.jpg)
ETC Components: Complex I2 e- from NADH are
transferred to Complex I
Protons are pumped across the inner mitochondrial membrane (IMM) by Complex I
![Page 8: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/8.jpg)
ETC Components: Qe- are transferred from
Complex I to ubiquinone (Q)
Q is a mobile component within the IMM
![Page 9: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/9.jpg)
ETC Components: Complex III
e- are transferred from Q to Complex III
Protons are pumped across the IMM by Complex III
![Page 10: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/10.jpg)
ETC Components: Cyt Ce- are transferred from
Complex III to cytochrome c (cyt c)
cyt c is a mobile component on the surface of IMM, in the intermembrane space
![Page 11: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/11.jpg)
ETC Components: Complex IV
e- are transferred from cyt c to Complex IV
Protons are pumped across the IMM by Complex IV
![Page 12: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/12.jpg)
ETC Components: O2
O2 is the final electron acceptor of the ETC
enough e- pass through the ETC to produce full H2O molecules
![Page 13: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/13.jpg)
FADH2 Pathway
FADH2 FAD
![Page 14: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/14.jpg)
ETC Components: Complex II2e- are transferred from
FADH2 to Complex II – can think of them passing directly to Ubiquinone
no protons are pumped across the IMM
e- are transferred from Complex II to Q and proceed through the rest of ETC
FADH2 FAD
![Page 15: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/15.jpg)
ETC Thermodynamics
Each electron transfer step is energetically favourable.
![Page 16: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/16.jpg)
Electrochemical Proton Gradient
![Page 17: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/17.jpg)
ETC Summary
1. NADH e- transferred to O2; three proton pumps activated
2. FADH2 e- transferred to O2; two proton pumps activated
3. electrochemical proton gradient formed across IMM
![Page 19: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/19.jpg)
Oxidative Phosphorylation
![Page 20: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/20.jpg)
Proton Motive Force: ChemiosmosisThe electrochemical gradient (chemiosmosis)
produced by the ETC can now be used to generate ATP through the process of oxidative phosphorylation (OXPHOS).
OXPHOS occurs through the enzyme complex ATP synthase.
OXPHOS Animation
![Page 21: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/21.jpg)
ATP Synthase ComplexTwo components:
1. F0 – proton channel / rotor embedded in IMM
2. F1 – catalytic sites that phosphorylate ADP to ATP
ATP synthase rotation
![Page 22: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/22.jpg)
ATP Productionoxidative phosphorylation - ATP is produced as
protons flow through ATP synthase.
In general:
1. 1 NADH 2.5 – 3 ATP molecules
2. 1 FADH2 1.5 – 2 ATP molecules
The ETC is coupled with ATP synthesis. The latter is dependent on the former.
![Page 23: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/23.jpg)
ATP ProductionCellular
Respiration Step
Energy Molecules Produced
ATP Totals
Glycolysis 2 ATP2 NADH
2 ATPspecial case
Oxidative Decarboxylation
2 NADH 6 ATP
Krebs Cycle 6 NADH2 FADH2
2 ATP
18 ATP4 ATP2 ATP
![Page 24: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/24.jpg)
Glycolysis NADHNADH produced in glycolysis must be transported
from the cytoplasm into the mitochondria to enter the ETC.
Two shuttle mechanisms:
1. glycerol phosphate shuttle
2. malate-aspartate shuttle
![Page 25: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/25.jpg)
Glycerol Phosphate Shuttle
![Page 26: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/26.jpg)
Malate-Aspartate Shuttle
![Page 27: Electron Transport Chain](https://reader035.vdocuments.net/reader035/viewer/2022062321/56812ff1550346895d9567a4/html5/thumbnails/27.jpg)
ATP Production SummaryCellular
Respiration Step
Energy Molecules Produced
ATP Totals
Glycolysis 2 ATP2 NADH
2 ATP4-6 ATP
Oxidative Decarboxylation
2 NADH 6 ATP
Krebs Cycle 6 NADH2 FADH2
2 ATP
18 ATP4 ATP2 ATP
TOTAL 36-38 ATP