electron transport chain ppt biochemistry
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ELECTRON TRANSPORT CHAIN
OR RESPIRATORY CHAIN
Dr Vijay MarakalaAssistant professor
BiochemistrySIMS&RC
CONTENTS
What is ETC Localization of ETC
Function of ETC
Components of ETC
Reaction of ETC
Oxidative phosphorylati
on
Mechanism of oxidative
phosphorylation
Reducing equivalents
What is ETC?
Localization of ETC
Function of ETC
ETC collects and oxidizes reducing equivalents with liberation of energy in the form of ATP
Components of ETC
Q=Ubiquinone or coenzyme Q
Complex-I
NADH - Q oxidoreductase
NADH FMN Fe-S CoQ
Complex-II Succinate Q oxidoreductase
Succinate FAD Fe-S CoQ
Complex-III
Q- Cytochrome c oxidoreductase
CoQ Fe-S Cyt.b Cyt.c1 Cyt.c
Complex-IV
Cytochrome oxidase orCytochrome aa3
Cyt.c Cyt.aa3 O2
Reactions of ETCAccepts and transfers one hydride ionNAD+
• One H+ and 2e-
Accepts and donates two hydrogenFMN/ FAD/
Q• H2 = 2H+ and 2e-
Accepts and transfers only one electronCyt/Fe-S
• One e-
Remember
Reactions of ETCSequence of reactions
NADH+ H+ donates electrons and protons
Formation of FMNH2
Collection of electrons from FMNH2 by Fe-S proteinCollection of reducing equivalents by Co Q
Removal of electrons by cytochromes
Reduction of oxygen to water
Formation of ATP
Coupling site for ATP synthesis
Fo F1 ATPase
F0
F1
Also called ATP synthase.
Embedded in the inner
membrane
Mechanism of oxidative phosphorylation
CHEMIOSMOTIC THEORY
Peter Mitchell1920-1992
Electrochemical gradient
Proton motive force
{ {P:O ratio
No of ATP synthesized per atom of oxygen[1/2O2]
Respiratory control
The regulation of the rate of oxidative phosphorylation by ADP level is called respiratory controlP:O ratio and Respiratory
control
How cytoplasmic NADH is
transported to mitochondria?
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