Chem 481 Test 4

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Chem 481 Test 4
2013-02-28 16:10:20
Biochemistry test BYUI

review questions based off of daily lectures in Chem 481. Starting with chapter 13.
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  1. How does the energy of the universe respond to an isolated reaction?
    • The Energy of the Universe is constant. It comprises the the systemic change in energy and the surrounding change in energy.
  2. Describe the Entropy of the universe:
    • The entropy (disorder) of the universe is increasing. This can also be said that:
  3. Describe the relation between The change in energy and the change in disorder:
  4. What can the ideal Gibbs free energy for a reaction be defined as?
  5. What is the difference between these two symbols:

    • is the change in energy under ideal conditions.
    • is the change in energy under real conditions.
  6. What are standard or ideal conditions to calculate the change in energy?
    • 298K
    • [1M]
    • pH=7.0
  7. How is the real change in energy calculated from the ideal change in energy?
    • Where Q is the mass action ratio of [P][R]
  8. What is the mass action ratio?
    It is equal to Q=[products]/[reactants]
  9. What is lnQ when P=R=1M?
    What is the real change in energy at these conditions?

  10. What is the  
    • It is the phosphorylation Potential.
    • Net Exergonic.
    • Ideal is -30.5 kJ/mol
  11. Describe the change in energy when bonds break:
    Bonds breaking always requires energy, thus it is endergonic.
  12. Describe the change in energy when bonds form:
    When bonds are formed unstable participants enter into stable forms. Entering this more stable form allows them to have a lower energy state. This is always Exergonic.
  13. If:
    What is:
  14. What is pyrophosphate?
  15. Which would be more exergonic, the hydrolysis of ATP into ADP and phosphate, or into AMP and pyrophosphate?
    • ATP into AMP and Pyrophosphate.
    • Comparing the ideal delta G:
    • ADP+P:AMP+PP
    •   -30.5:-45.6
    •        2:3
  16. Generally will have more or less resonance forms make a product more exergonic?
    • More resonance=more stable.
    • more stable=lower delta G.
  17. does sulfur make strong or weak pi Bonds?
    weak pi bonds.
  18. What is the role and final change in energy for an adenylate kinase reaction?
  19. Would ATP into ADP+P or GTP into GDP+P be more exergonic?
    They would be energetically identical because all NTP's are more or less energetically identical.
  20. What does phosphocreatine do?
    • It allows ADP to be turned into ATP in muscles.
  21. What are 2 ways of determining the oxidation states?
    • 1. Standard electron assigning (H+1, O-2)
    • 2. Determining the electron position based on each bond:
  22. How would the electrons be assigned for ethanol?
  23. What are the oxidation numbers for the atoms in ethanol?
    • O (6-8)=-2
    • C1(4-5)=-1
    • C2(4-7)=-3
    • H1-6(1-0)*6=+6
    • Net=0
  24. What does a concerted reaction mean?
    That it happens all in 1 step
  25. What is Hydride?
    Is it a strong or weak leaving group?
    • H: Hydrogen with both electrons.
    • H-
    • Strong leaving group.
  26. What 4 things would indicate a REDOX reaction?
    • 1. Direct transfer of electrons
    • 2. Hydrogen atoms are transfered as H+ e- pairs.
    • 3. Hydride ions are transfered (NADH NAD+)
    • 4. Direct combination with O2
  27. What does NAD stand for?
    Nicotinamide Adenine Dinucleotide.
  28. Is nicotinamide a purene or a pyrimadine.
    • It is a special pyrimadine called a pyradine.
  29. What is the structural change between NAD+ and NADH?
    • the pyradine is reduced by Hydride at the 4 position. resulting in NADH and H+
  30. What is the structural difference between NAD+ and NADP+?
    • Hydroxyl is eserified with phosphate.
  31. What wavelength does Oxidized NAD+ absorb?
  32. What wavelength does Reduced NADH absorb?
    around 340 and also 260.
  33. What is E'o?
    Standard reduction potential.
  34. What is E?
    real reduction potential.
  35. What is the equation to give the real reduction potential?
  36. how does the change in reduction potential relate to reduced reduction potential and the oxidized reduction potential?
  37. How does the change in energy relate to the change in reduction potential?
  38. How do you convert from C to K?
    • C+273=K
    • K-273=C
  39. What is the numerical value of R
  40. What is the numerical value of F?
  41. What are two ways to regulate a pathway?
    • 1. Changing the number of the enzymes.
    • 2. Changing Enzyme activity.
  42. What process produces NADPH?
    The pentose phosphate pathway.
  43. What is the preparatory phase of glycolysis?
    • This refers to the first 5 steps.
    • 2 ATP are used.
    • 2 glyceraldehyde-3-phosphates are produced.
    • Has 2 "commitment steps"
  44. Describe the payoff phase of glycolysis:
    • This refers to the last 5 steps.
    • Everything happens x2.
    • Total: 4 ATP produced, 2 NADH, 2 pyruvate.
    • Involves only 1 irreversible step.
  45. What do the exact values of the delta G depend on?
    They depend on specific conditions, like concentration or heat in the system.
  46. What steps of glycolysis Involve large changes in the change in energy?
    • 1 Glucose+ATP->glucose-6-phophate+ADP
    • 3 Fructose-6-phosphate+ATP->fructose 1,6-bisphosphate+ADP
    • 10 Phosphophenolpyruvate+ADP->pyruvate+ATP
  47. What enzyme catalyses the first step in glycolysis?
  48. What enzyme catalyses the 3rd step in glycolysis?
    • Phosphofructokinase-1
    • (PFK-1)
  49. What enzyme catalyzes the 10th step in glycolysis?
    • Pyruvate Kinase.
    • Named for reverse reaction.