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  1. System
    is the part of universe that is under study
  2. Surroundings
    is everything else in the universe
  3. Isolated system
    can’t exchange matter or energy with the surroundings
  4. Closed system
    it is possible that it will exchange energy, but not matter, with the surroundings
  5. Open system
    may exchange matter, energy, or both with the surroundings
  6. First Law of thermodynamics
    in an isolated system, the energy is not created nor destroyed, it is conserved
  7. Internal Energy (E)
    keeps track of the heat transfer and work performed in thermodynamics systems
  8. First Law of thermodynamics
    ∆E =
    E2 – E1 = q + w
  9. Mechanical work
    movement through some distance caused by the application of the force
  10. Relationship of work with pressure and volume
    w = -P∆V
  11. If the work is not done by the system the sign is
  12. If the work is done by the system the sign is
  13. Types of work
    • mechanical
    • electrical
    • magnetic
    • chemical
  14. Enthalpy
    • heat exchange at constant pressure
    • H = E + PV
    • H = q
  15. For solutes in a solution, the standard state is .
    • normally unit activity or 1M concentration
    • “ ° ”, ∆E °, ∆H°, etc
  16. Second Law of Thermodynamics
    the system tends to proceed from an ordered state to a disordered state
  17. Entropy (∆S)
    measure of disorder and randomness in the system or surroundings
  18. Ordered state
    low entropy state
  19. Disordered
    high entropy state
  20. Reactions with large positive entropy changes are
    more likely to occur than reactions with small positive entropy
  21. Third Law of Thermodynamics
    the entropy of any crystalline, perfectly ordered substance must approach zero as the temperature approaches 0K
  22. Heat capacity (Cp)
    is the amount of heat needed for one mole of any substance to raise the temperature by one degree
  23. One can calculate the entropy change if the
    • enthalpy and the free energy change are known
    • ∆G = ∆ H - T∆S
  24. ∆G = 0
    the reaction is in equilibrium
  25. If ∆G < 0
    the process goes toward the direction written. (exergonic)
  26. If ∆G > 0
    the process goes toward the reverse direction. (endergonic)
  27. Positive ∆H for the protein unfolding
    breaking of hydrogen bonds or exposure of hydrophobic groups to water
  28. Phototropic organisms
    absorb light energy directly form the Sun
  29. Chemotrophic organisms
    feed on phototropic organisms and release store energy in a series of oxidative reactions
  30. Chemical reasons for large ∆G°’ values
    • destabilization of the reactant due to electrostatic repulsions
    • stabilization of the products by ionization and resonance
    • entropy factors due to hydrolysis and ionization.
  31. Enol Phosphates
    important intermediate of carbohydrate metabolism
  32. In hydrolysis as pH increases, ∆G°becomes
    more negative for every pH unit increase
  33. If ∆E°’ is negative
    the flow goes toward the reference cell because the sample donates electrons
  34. If ∆E°’ is positive
    the flow goes toward the sample cell because the sample accepts electrons
Card Set:
2013-09-29 00:55:23
Thermodinamics Biochemistry

Biochemistry, Thermodinamics, systems
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