1. Metabolism: An Introduction
Totality of an organism’s processes
Molecular interactions make this an emergent property
Concerned with managing cellular material and energy
Anabolic Pathways
Catabolic Pathways
These Anabolic/Catabolic reactions can be coupled so that energy released from a catabolic rx can drive an anabolic rx.

2. Catabolic Pathways
RELEASE ENERGY by breaking down complex molecules to simpler ones

3. ANABOLIC PATHWAYS
CONSUME ENERGY to build complicated molecules from simpler ones

4. Organisms Transform Energy
Energy: Capacity to do work
Kinetic Energy: Energy in the process of doing work (energy of motion) ex.:Light,Thermal.
Potential Energy: Energy of position (energy due to arrangement or location). Ex.:Rock on hill, chemical energy
ENERGY CAN BE TRANSFORMED FROM ONE FORM TO ANOTHER. Ex: Gas-motion

5. Energy Transformations and Thermodynamics
Thermodynamics: The study of energy transformations
First Law of Thermodynamics: Energy can’t be created or destroyed, only transferred or transformed
Second Law of Thermodynamics: Every energy transfer increases ENTROPY
Entropy: Quantitative measure of disorder (proportional to randomness)

6. More Thermodynamics Vocab.
Closed System: Collection of matter being studied which is isolated from the surroundings
Open System: A system in which energy can be transferred from the system and its surroundings

7. ENTROPY
The entropy of a system may DECREASE, but the entropy of the system plus its surroundings must always INCREASE.
Animals:
Maintain highly ordered structure at the expense of their surroundings
Take in complex high energy molecules as food and extract energy in order to create and maintain order
Return simple low energy molecules and heat to surroundings

8. Gibbs-Heimholtz equation:
FREE ENERGY
The amount of energy that is available to do work
Free Energy:G
Total Energy or Enthalpy: H
Temperature in Kelvin Degrees: T
Entropy: S
Free energy is the difference between the total energy and the energy NOT available to do work.
Gibbs-Heimholtz equation: G S H- T =

9. Significance of Free Energy
Indicates a maximum amount of a system’s energy which is available to do work
Indicates whether a reaction will occur spontaneously or not
A spontaneous reaction is one that will occur without any additional energy
The change in Free energy of a system DECREASES in a spontaneous reaction.
A decrease in enthalpy (or total energy) or a n increase in entropy reduce the free energy, and make a spontaneous more likely
Increased Temperature favors spontaneity
These reactions tend toward a more stable state

10. Free Energy and Equilibrium
There is a relationship between chemical equilibrium and free energy change
As the reaction approaches equilibrium, the free energy decreases
As a reaction is pushed away from equilibrium, free energy increases.
AT equilibrium, there is no net change in the system (0 change in free energy)

11. Free Energy and Metabolism
EXERGONIC REACTIONS: A reaction with a net LOSS of free energy
Spontaneous
The change in Free energy (downhill) is the max. amount of work the Rx can do
Products have less free energy than rectants
ENDERGONIC REACTIONS: An energy requiring reaction that occurs with a net GAIN of free energy
Absorbs energy
Products store more free energy
Non-spontaneous
The change in free energy (uphill) is the min. amount of energy required to drive the rx

12. What the………..(O.K., here’s some examples)
Burning (oxidation) of one mole of glucose: EXERGONIC and releases 686 Kcal/mol. Actually Free energy is said to be NEGATIVE or-686Kcal/mol.
Production of 1 mole of glucose is ENDERGONIC and requires the energy input of +686Kcal/mole

13. Energy Units Joule(J): .239 calorie Kilojoule(kJ): 1000J or .239 Kcal
Calorie(cal): 4.184J

14. METABOLIC DISEQUILIBRIUM
At equilibrium the system can’t do work: Change of free energy is 0.
Necessity of life: A cell at total equilibrium is dead
These reversible reactions are pulled one way or the other because the products of 1 become the reactants for another