Metabolism & Energy
Relationships
1
Metabolism and Energy
Relationships
Signaling Molecules Regulate
Fuel Uptake and Efficiency
Leptin deficient mouse
Metabolism and Energy
• Information Metabolism (Genetic
Continuity and Evolution)
• Intermediary Metabolism
(Interconversion of Chemical
Metabolites Used to Obtain Energy)
Information
Metabolism
Storage
of Genetic
Information
Intermediary
Metabolism
Interconversions of chemical
intermediates catalyzed by
enzymes (proteins)
Enabling Technology:
Radioactive Tracers
Free energy decreases
spontaneously
Storage and Interconversion of
Energy
ATP
Energy
ATP Is the Energy Currency of the Cell
Electrochemical Potential
Energy = Concentration Gradient + Charge Gradient
Interconversion Between Electrochemical
Gradients and Bond Energy
(Ion Pump)
Brownian Motions Drives
Molecular Machines (Ion Pumps)
Metabolic Strategies: Regulate
Flux Through the System
A ÅÆ B Æ C ÅÆ D ÅÆ E Æ F ÅÆ G ÅÆ H Æ I ÅÆ J
Regulated Steps in Pathway Involve Energy Expenditure
Steps That Are Readily Reversible Are Not Regulated
Regulation of Metabolism
• Post-translational Modifications
(Proteolytic Activation; Phosphorylation)
• Allosteric Regulation
(Binding of Small Molecules)
• Changes in Expression Levels
(Transcriptional Activation)
Phosphorylation Promotes
Complex Formation
Post-translational
Modifications
Allosteric
Regulation
Oligomeric Enzyme
ADP
F 1,6 P
Allosteric binding site
Substrate binding
site
Transcriptional
Activation
Substrate Channeling
Amplification Involves Multiple
Types of Regulation
Cells Subdivide Their Tasks Into
Cellular Compartments That
Facilitate Coordinate Regulation
of Metabolism
Location, Location, Location
In General
• Catabolic Reactions
Take Place in the
Mitochondria
• Anabolic Reactions
Take Place in the
Cytosol
Compartmentalization
Electrons Are
Shuttled Through
Mitochondria
Electrochemical Gradient Is Used
to Make ATP
ATP Synthase Converts
Electrochemical Gradient Into ATP
Binding Change Mechanism
Rotary Motion Was Directly
Measured
Respiratory Control Mechanisms
Regulate Rates of ATP Synthesis
cytosol
OM
IM
Generation of Oxygen Radicals
During Normal Metabolism
O2
O2•
Sensors of Oxidative Stress Down-regulate
Energy Utilization and -Decrease Oxidative Stress
Through Respiratory Control Mechanisms
NO•
+
O2• -
Decreased
ATP
Utilization
ONOOCO2
HO
NO
2