1BMS1153 BL1-Energy Metabolism
1BMS1153 BL1-Energy Metabolism
1BMS1153 BL1-Energy Metabolism
BETA OXIDATION
ATP
92% of ATP is produced by Ox-Phos in
mitochondria.
Compounds with high energy bonds are said to have high
group transfer potential.
G = -7.3kcal/mole
O O O N N
-O P O P O P O CH2
adenine
O
O- O- O- H H
H H
phosphoanhydride OH OH
bonds (~) ribose
Phosphocreatine (creatine phosphate)
another compound with a "high energy" phosphate
linkage, is used in nerve & muscle for storage of ~P
bonds.
phosphocreatine
Oxidative phosphorylation
Transduction of energy from the oxidation
of NADH and FADH2 via the ETC system to
the phosphorylation of high energy bonds
of ATP.
The process by which the energy from
fuel oxidation ( NADH and FADH2 from
Glycolysis, beta-oxidation and TCA ) is
transduced to high energy phosphate
bonds of ATP via the electron transport
chain system in the inner mitochondrial
membrane.
Electron transport chain
The assembly of protein complexes in the
inner membrane of mitochondria that
participate in the energy transduction process
via cascade of oxidation-reduction steps.
NADH
ADP + Pi ATP + H2O
-320mV
SYNTHASE
DGo
1.14volts
PROTONMOTIVE FOR
-52.4kcal
ATP synthase
III IV
I
II
THE ELECTRON
TRANSPORT CHAIN
The electron carriers of the
electron transport chain are
organized into four multi protein
complexes.
These complexes are connected by
two mobile electron carriers,
ubiquinone and the Fe - heme
containing protein cytochrome C.
Ubiquinone diffuses freely in the
hydrocarbon core of the inner
mitochondrial membrane.
Cytochrome C (Cyt C) diffuses
Electron Transport Chain
(ETC)
Assembly of large protein complexes ( I, II,
III and IV ), Cyto C and a hydrophobic
coenzyme Q (ubiquinone with 10
isoprenoid units).
Complex I is e-acceptor for NADH.
Complex II is e-acceptor for FADH2.
These components are arranged
sequentially embedded in the inner
mitochondrial membrane.
ATP synthase is a multi subunits complex
with Fo as proton channel and F1 is the
enzyme ATPase.
18
COMPLEX 1 COMPLEX III COMPLEX IV ATPase complex
Fo
Co Q CYTO C
F1
intermembrane
Fo
F1
Mitochondrial matrix
The F0F1 ATP synthase
Cyto C
O2
Oxidation / Reduction
Uncoupler - Dinitrophenol