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Energy andmetabolism
http://bcs.whfreeman.com/lehninger (Ch 13)
http://bcs.whfreeman.com/biochem5 (Ch14)
http://www.genome.ad.jp/kegg
S. 14.2.
Reminder in Thermodynamics
• First Law (conservation of energy)• Second Law (entropy of the Universe increases in spontaneous processes)
• concepts of open, closed and isolated systems• sign conventions for energy changes
• Free energy (G) (exergonic - endergonic)• Enthalpy (H) (exothermal - endothermal)• Entropy (S)
G = H - TS = - RT lnQ
See Living Graph 13-3
Entropy
1. Teakettle
2. Glucose oxidation
3. Entropy (randomness) and information
There is a tide in the affairs of men,Which, taken at the flood, leads on to fortune;Omitted, all the voyage of their lifeIs bound in shallows and in miseries. (Brutus) - Shakespeare: Julius Caesar, Act 4, Scene 3
ENERGY CONTENT(fuels, sunlight)
WORK
chemical synthesis
mechanical work
osmotic and electricgradients
transmission of genetic information
light
HEAT ENTROPY CHANGE
increases in the surroundings:catabolic end products are small
decreases in the cell :anabolic end products are large
sophisticated molecules
L. II-3. S. 14-12.
L. 1-26. See also “Energetic Coupling” among “Conceptual Insights” on Stryer website
Free energy in coupled reactions
L. 13-8,12
L. 13.1.
L. 13.2.
ATP hydrolysis and phosphorylation potential
See also Living Figure “Box 13-1”
L. 13-10,11
L. T-13-6
L. 13-9
L. 13-3,4
L. 13-5
Reperfusion in the presenceof cardioprotective agents
Ischaemia
Normoxia
CrP-ATP -ATP -ATP
In situ study of energy metabolism:Monitoring of high-energy phosphorus metabolite levels
in perfused rat hearts using 31P NMR spectroscopy
Reperfusion
PCr
Pi
ATP ATP ATP
Effect of PARP inhibitors on the recovery of creatine phosphate during ischemia-reperfusion
0
20
40
60
80
100
120
3 6 9 3 14 25 3 6 9 12 15
perfusion time (min)
CrP
( %
of n
orm
oxi
c va
lue)
Control
4-OHQ
HO-3089
normoxia ischemia reperfusion
*
*p<0.05
Effect of PARP inhibitors on the recovery of ATP during ischemia-reperfusion
0
20
40
60
80
100
120
3 6 9 3 14 25 3 6 9 12 15
perfusion time (min)
AT
P (
% o
f n
orm
oxi
c v
alu
e)
Control
4-OHQ
HO-3089
normoxia ischemia reperfusion
*
* p<0.05
Effect of PARP inhibitors on the utilization of inorganic phosphate
during ischemia-reperfusion
0
20
40
60
80
100
120
3 6 9 3 14 25 3 6 9 12 15
perfusion time (min)
Pi (
% o
f e
nd
-isc
he
mic
val
ue
)
Control
4-OHQ
HO-3089
normoxia ischemia reperfusion
*
* p<0.05
L. 13-6,7
Electron transfer as a form of energy transfer
Electron affinity, oxidative/reductíve capacity electromotive force
E = E° +0.026V/n ln[ox]/[red]
G = -nF E
Deficiency: pellagra (dermatitis, diarrhea, dementia, death)
Regulation of metabolic pathways• controlling the amounts of enzymes• controlling the catalytic activities of enzymes• controlling the accessibility of substrates
Role of energy content in regulation
Online resources:
http://bcs.whfreeman.com/lehninger (Ch13)
http://bcs.whfreeman.com/biochem5 (Ch14)
For online quizzing give:[email protected] instructor’s e-mail address
