3. 1. Describe briefly the function of the electron transport chain
during aerobic respiration.
2. Describe briefly the chemio-osmotic theory of generation of
ATP as a result of an electron transport chain.
3. Compare where the electron transport chain occurs in
prokaryotic cells and in eukaryotic cells.
4. Compare and contrast between Malate-Aspartate shuttle
and Glycerol-3-phosphate shuttle
5. Understand the metabolic profiles in brain, skeletal muscles,
heart muscle, liver and adipose tissue
6. Describe metabolic control by hormones
7. Describe metabolic responses to stress condition
8. Identify biochemical factors in obesity
10. Quickly retrieve and fill in the blanks
Amino acid
degradation
Glycolysis β- oxidation
Location
Energy
molecules
End product(s)
10
11. List all products/intermediate from the catabolism reactions that can be further
breakdown to form MORE ENERGY molecules
Molecules/
Intermediates
Originate from
_______________
catabolism
Enter _____________ pathway/cycle
via________ reaction
Krebs cycle/TCA cycle via transition
reaction to form acetyl CoA and +
OAA citrate
Glucose /Glycolysis
Pyruvate
11
12. Flow of discussion
1. Krebs Cycle/ TCA Cycle
2. Electron transport system
3. Oxidative phosphorylation to form ATP from
i. Mitochondrial generated NADH and FADH2
ii. Malate-Aspartate shuttle
iii. Gylcerol-3-phosphate shuttle
12
34. 6C
4C
2C
6C
5C
4C
4C
4C
4C
5. Succinyl-CoA is cleaved
[succinyl-CoA synthetase]
-GTP
6. Succinate is oxidized
[succinate dehydrogenase]
-1st FADH2
7.Fumarate is hydrated
[fumarase]
8. Malate is oxidized
3rd NADH
From one cycle, how many NADH, FADH2 and
GTP are formed ?
At which stage ?
35. What are the output from one cycle?
_______________________________
35
39. 3 minutes – Quick D:
Produce the best definition;
ELECTRON TRANSPORT CHAIN (ETC) is
……………………………. (not more than 20 words)
39
40. ETS may be found in:
-the cytoplasmic membrane in
_____________ cells
-the inner membrane of mitochondria
in _______________ cells.
40
41.
42. Depending on the type of cell, the electron transport chain may
be found in the cytoplasmic membrane or the inner membrane of
mitochondria.
In prokaryotic cells
protons are transported from the cytoplasm of the
bacterium across the cytoplasmic membrane to the periplasmic
space located between the cytoplasmic membrane and the cell
wall .
In eukaryotic cells
protons are transported from the matrix of the
mitochondria across the inner mitochondrial membrane to the
intermembrane space located between the inner and outer
mitochondrial membranes
45. In an electron transport system, electrons are passed from carrier to carrier
through a series of oxidation-reduction reactions.
During each transfer, some energy is released.
45
47. I = NADH dehydrogenase
II = Sucinate dehydrogenase
complex -coenzyme Q
III = cytochrome b
IV = cytochrome c
V = cytochrome oxidase
oxidation
reduction
I
IV
V
III
II
NADH + H+
NAD+ + 2H+
2e ATP
ADP +P
2e
2e ATP
ADP +P
2e
H2O
½O2 + 2H+
2e
ATP
ADP +P
47
48. oxidation
reduction
IV
V
III
II
2e
2e ATP
ADP +P
2e
H2O
½O2 + 2H+
2e
ATP
ADP +P
FADH2
FAD + 2H+
Remember this:
FADH2 is a two
electron donor
II = Sucinate dehydrogenase
complex -coenzyme Q
III = cytochrome b
IV = cytochrome c
V = cytochrome oxidase
48
49. 1. flow of electrons from NADH (or FADH2) to molecular oxygen via the
ETC
Release large amounts of energy to drive the second process:
2. Phosphorylation of ADP by inorganic phosphate to form ATP
Catalyzed by inner mitochondrial membrane enzyme, ATP synthase
Q: State the TWO activities combined in Oxidative
phosphorylation
49
50. For animation visit this URL:
http://www.wiley.com/legacy/college/boyer/0470003790/animations/electron_transport/el
ectron_transport.htm
http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/a
nimations/oxidative/oxidativephosphorylation.html
50
http://www.wiley.com/college/boyer/0470003790/animations/electron_transport/electron_transp
ort.swf
51. Source of NADH and FADH2 energy molecules for
Oxidative phosphorylation to form ATP are
generated in:
1. Mitochondria
2. Cytoplasm
Malate-Aspartate shuttle
Gylcerol-3-phosphate shuttle
53. Complete oxidation of glucose depend on the cellular
location of its catabolism
Either yields 36 ATP or 38 ATP
Why?
1. NADH generated outside mitochondria cannot be transported
through the inner mitochondrial membrane
2. Therefore cytoplasmic NADH must be recycled by
electron shuttle system (ESS)
3. ESS carry electrons through the membrane in form of
reduced substrates
56. Shuttle
system
Malate-Aspartate shuttle Glycerol-3-phosphate shuttle
Location Heart and liver Skeletal muscle and brain
Pathway Electrons from cytoplasmic NADH are
carried by malate through the inner
membrane
Electrons from cytoplasmic NADH are
oxidized to form Glycerol-3-phosphate
Malate is oxidized in matrix to form
OAA
Glycerol-3-phosphate is oxidized to form
DHAP
Enzyme used is mitochondrial malate
dehydrogenase
an NAD-linked enzyme
Enzyme used is glycerol-3-phosphate
dehydrogenase
a FAD-linked enzyme
Electrons in NADH enter ETC Electrons in FADH2 enter ETC
ATP 3 ATP are formed 2 ATP are formed
57. Shuttle
system
Malate-Aspartate shuttle Glycerol-3-phosphate shuttle
Location Heart and liver Skeletal muscle and brain
Pathway Electrons from cytoplasmic NADH are
carried by malate through the inner
membrane
Electrons from cytoplasmic NADH are
oxidized to form Glycerol-3-phosphate
Malate is oxidized in matrix to form
OAA
Glycerol-3-phosphate is oxidized to form
DHAP
Enzyme used is mitochondrial malate
dehydrogenase
an NAD-linked enzyme
Enzyme used is glycerol-3-phosphate
dehydrogenase
a FAD-linked enzyme
Electrons in NADH enter ETC Electrons in FADH2 enter ETC
ATP 3 ATP are formed 2 ATP are formed
