1. Cellular Energy and Metabolism

2. Metabolism/Bioenergetics
Metabolism: The totality of an organism’s chemical processes; managing the material and energy resources of the cell
Catabolic pathways: degradative process such as cellular respiration
releases energy
Anabolic pathways: building process such as protein synthesis; photosynthesis
consumes energy

3. Types of NRG Energy (E) = capacity to do work
Kinetic energy~ energy of motion
Potential energy~ stored energy

4. Thermodynamics Thermodynamics = study of E transformations
1st Law: conservation of energy; E transferred/transformed, not created/destroyed
2nd Law: transformations increase entropy (disorder, randomness)
Combo: quantity of E is constant, quality is not

5. Free energy
Free energy (G) = portion of system’s E that can perform work at constant temp. and pressure
ΔG = ΔH –TΔS
Δ = change in
H = enthalpy (total E of system)
S = entropy (disorder)
T = absolute temperature (Kelvin)
If ΔG < 0, the reaction will occur spontaneously
If ΔG > 0, the reaction will not occur spontaneously

6. Moving Toward Equilibrium

7. Exergonic vs. Endergonic
Exergonic reaction: net release of free E to surroundings
ΔG < 0 (spontaneous)
Endergonic reaction: absorbs free E from surroundings
ΔG > 0 (not spontaneous)

8. Adenosine Triphosphate
ATP tail: high negative charge, high repulsion
ATP hydrolysis is exergonic
Releases 7.3 kcal of E per mole of ATP

9. Energy coupling: use of exergonic process (ATP hydrolysis) to drive an endergonic one

10. Energy Coupling Phosphorylation ATP hydrolysis creates E
Enzymes transfer P to a reactant
Creates a phosphorylated Intermediate (less stable)
Reaction occurs spontaneously