I ELECTRON TRANSPORT CHAIN (ETC) Dr. Samah Kotb Lecturer of Biochemistry 2015 Cellular Biochemistry and metabolism 2 CLS 333
Electron Transport Chain (ETC) C HAPTER 7
ELECTRON TRANSPORT CHAIN (ETC) The electron transport chain is a series of protein complexes embedded in the mitochondrial membrane.
ELECTRON TRANSPORT CHAIN (ETC) In the TCA cycle 3 molecules of NADH and one of FADH2 are Produced. The Hydrogen atoms on these reduced coenzymes are removed and split into protons + electrons. The protons dissolve and disappear in the aqueous medium of the mitochondrial matrix. The electrons are transported along a chain of protein type molecules attached in a specific sequence to the inner mitochondrial membrane. At the end of the chain the electrons are received by oxygen which gets reduced to water.
At the electrons move from one membrane of the chain to the next, they lose energy. This energy is used by the cell to synthesize ATP from ADP and Pi. There are 7 member molecules of the chain. Electrons coming from NADH travel enough distance and loose enough energy to allow the cell to synthesize 3 ATP molecules. However electrons coming from FADH 2 will lose enough energy to allow the cell to synthesize only 2 ATP molecules. ELECTRON TRANSPORT CHAIN (ETC)
The electrons carried on NADH after adding energy will synthesis 3 ATP. The electrons carried on FADH 2 after adding energy will synthesis 2 ATP.
Number of ATP molecules synthesized as a result of complete degradation of one glucose molecule Number of ATP molecules synthesized as a result of complete degradation of one glucose molecule 1) Glycolysis: ELECTRON TRANSPORT CHAIN (ETC)
Number of ATP molecules synthesized as a result of complete degradation of one glucose molecule 2. Pyruvate Oxidation
3. TCA cycle Number of ATP molecules synthesized as a result of complete degradation of one glucose molecule
Total Net: Glycolysis = 2 ATP Reaction 6 (ETC) = 6 ATP Pyruvate Oxidation (ETC) = 6 ATP 2 turns of TCA cycle = 24 ATP TOTAL = 38 ATP
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