Title: Electron Transport Chain (Respiratory Chain) - exercise -
1Electron Transport Chain(Respiratory Chain)-
exercise -
2Respiratory chain (RCH)
- is found in all cells
- is located in a mitochondrion
- includes enzymes integrated in the inner
mitochondrial membrane - produces reducing equivalents (NADHH, FADH2)
3Respiratory chain (RCH)
- is found in all cells
- is located in a mitochondrion
- includes enzymes integrated in the inner
mitochondrial membrane - produces reducing equivalents (NADHH, FADH2)
4The figure is found at http//plaza.ufl.edu/tmulli
ns/BCH3023/cell20respiration.html (December 2006)
5Respiratory chain (RCH)
- belongs among oxidative pathways
- can proceed under both aerobic and anaerobic
conditions - is a reversible pathway
- needs oxygen (O2) for its function
6Respiratory chain (RCH)
- belongs among oxidative pathways
- can proceed under both aerobic and anaerobic
conditions - is a reversible pathway
- needs oxygen (O2) for its function
7? reducing properties
Redox potential E
Gibbs energyG
? oxidizing properties
The figure is found at http//www.grossmont.net/cm
ilgrim/Bio220/Outline/ECB2FiguresTables_Ed2-Ed1/C
hapter14_13/REDOX_POTENTIALS_ElectronTransportChai
n_Fig14-21.htm (December 2006)
8The figure is found at http//academic.brooklyn.cu
ny.edu/biology/bio4fv/page/mito_ox.htm (December
2006)
9Enzymes of the RCH
- belongs among oxidoreductases
- can transfer either H or electrons
- are called Complex I, II, III and IV
- transfer protons and electrons in the same
direction
10Enzymes of the RCH
- belongs among oxidoreductases
- can transfer either H or electrons
- are called Complex I, II, III and IV
- transfer protones and electrones in the same
direction
11proton H electron e-
Cytochrome c is drawn wrongly! It is found in
the intermembrane space, bound to the inner
mitochondrial membrane
The figure is adopted from the book Devlin, T.
M. (editor) Textbook of Biochemistry with
Clinical Correlations, 4th ed. Wiley-Liss, Inc.,
New York, 1997. ISBN 0-471-15451-2
12The function of the RCH
- is to regenerate NAD from NADH
- is to regenerate NADP from NADPH
- is to regenerate FAD from FADH2
- is to finish oxidation of energy substrates and
conserve their energy in a form of ATP
13The function of the RCH
- is to regenerate NAD from NADH
- is to regenerate NADP from NADPH
- is to regenerate FAD from FADH2
- is to finish oxidation of energy substrates and
conserve their energy in a form of ATP
14In reactions of the RCH
- oxygen is reduced to H2O
- protons (H) are transfered into an intermembrane
space - ATP is produced by the Complex I
- all reduced coenzymes (NADHH and FADH2) are
reoxidized by the same mechanism
15In reactions of the RCH
- oxygen is reduced to H2O
- protons (H) are transfered into an intermembrane
space - ATP is produced by the Complex I
- all reduced coenzymes (NADHH and FADH2) are
reoxidized by the same mechanism
16The figure is found at http//www.cellml.org/examp
les/images/metabolic_models/the_electron_transport
_chain.gif (December 2006)
17Choose correct statement
- Complex I transfers H into an intermembrane
space - Complex II transfers H into an intermembrane
space - Coenzyme Q accepts e- from both Complex I and
Complex II - Complex IV transfers electrones to oxygen
18Choose correct statement
- Complex I transfers H into an intermembrane
space - Complex II transfers H into an intermembrane
space - Coenzyme Q accepts e- from both Complex I and
Complex II - Complex IV transfers electrones to oxygen
19proton H electron e-
Cytochrome c is drawn wrongly! It is found in
the intermembrane space, bound to the inner
mitochondrial membrane
The figure is adopted from the book Devlin, T.
M. (editor) Textbook of Biochemistry with
Clinical Correlations, 4th ed. Wiley-Liss, Inc.,
New York, 1997. ISBN 0-471-15451-2
20Citrate cycle (CC) and the RCH are interconnected
- by CO2 (produced by CC, used by RCH)
- by NADH (produced by CC, used by RCH)
- an enzyme succinate dehydrogenase
- ATP (produced by RCH, used by CC)
21Citrate cycle (CC) and the RCH are interconnected
- by CO2 (produced by CC, used by RCH)
- by NADH (produced by CC, used by RCH)
- an enzyme succinate dehydrogenase
- ATP (produced by RCH, used by CC)
22Citrate cycle
succinate DH
The figure is found at http//www.cellml.org/examp
les/images/metabolic_models/the_electron_transport
_chain.gif (December 2006)
23Adenosine triphosphate (ATP)
- can be produced only in a cooperation with the
RCH - can be synthesized only under aerobic conditions
- is formed from ADP by addition of one phosphate
- is transported from a mitochondrion into a
cytoplasm by exchange with ADP
24Adenosine triphosphate (ATP)
- can be produced only in a cooperation with the
RCH - can be synthesized only under aerobic conditions
- is formed from ADP by addition of one phosphate
- is transported from a mitochondrion into a
cytoplasm by exchange with ADP
25ATP-ADP translocase
The figure is adopted from the book Devlin, T.
M. (editor) Textbook of Biochemistry with
Clinical Correlations, 4th ed. Wiley-Liss, Inc.,
New York, 1997. ISBN 0-471-15451-2
26When the term is used it always means ATP
synthesis
- phosphorylation
- oxidative phosphorylation
- aerobic phosphorylation
- substrate level phosphorylation
27When the term is used it always means ATP
synthesis
- phosphorylation
- oxidative phosphorylation
- aerobic phosphorylation
- substrate level phosphorylation
28Oxidative phosphorylation
- needs proton gradient on the inner mitochondrial
membrane - is catalyzed by ATP synthase
- can be interrupted by uncoupling proteins (UCP)
- means ATP synthesis in any oxidative metabolic
pathway
29Oxidative phosphorylation
- needs proton gradient on the inner mitochondrial
membrane - is catalyzed by ATP synthase
- can be interrupted by uncoupling proteins (UCP)
- means ATP synthesis in any oxidative metabolic
pathway
30The figure is adopted from the book Devlin, T.
M. (editor) Textbook of Biochemistry with
Clinical Correlations, 4th ed. Wiley-Liss, Inc.,
New York, 1997. ISBN 0-471-15451-2
31inner mitochondrial membrane
ATP synthase
The figure is found at http//plaza.ufl.edu/tmulli
ns/BCH3023/cell20respiration.html (December 2006)
32Uncoupling proteins(UCP) separate RCH from ATP
synthesis(the synthesis is interrupted)
energy from H gradient is released as a heat
The figure is found at http//departments.oxy.edu
/biology/Franck/Bio222/Lectures/March23_lecture_sh
uttles.htm (December 2006)
33ATP can be formed by the reactions
- glucose-6-P ADP ? glucose ATP
- succinylCoA GDP ? succinate GTP
- GTP ADP ? GDP ATP
- ADP ADP ? ATP AMP
34ATP can be formed by the reactions
- glucose-6-P ADP ? glucose ATP
- succinylCoA GDP ? succinate GTP
- GTP ADP ? GDP ATP
- ADP ADP ? ATP AMP (adenylate kinase
myokinase)
35Oxidation of NADHH in the RCH produces more ATP
than oxidation of FADH2 because
- higher proton gradien is made by oxidation of
NADHH - NADHH transfers H to different Complex of the
RCH than FADH2 - more protons are transported to the intermembrane
space if NADHH is oxidized - more e- are transfered from NADHH to O2
36Oxidation of NADHH in the RCH produces more ATP
than oxidation of FADH2 because
- higher proton gradien is made by oxidation of
NADHH - NADHH transfers H to different Complex of the
RCH than FADH2 - more protons are transported to the intermembrane
space if NADHH is oxidized - more e- are transfered from NADHH to O2
37FADH2
The figure is found at http//web.indstate.edu/thc
me/mwking/oxidative-phosphorylation.html
(December 2006)
38Choose correct statement(s) about regulation of
RCH and ATP synthesis
- ? O2 decreases the pathways
- uncoupling proteins increases ATP synthesis
- ? ADP increses ATP synthesis
- ? NADHH/NAD increases the pathways
39Choose correct statement(s) about regulation of
RCH and ATP synthesis
- ? O2 decreases the pathways
- uncoupling proteins increases ATP synthesis
- ? ADP increses ATP synthesis
- ? NADHH/NAD increases the pathways