Intro to metabolism.txt

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  1. What are two ways that ATP is hydrolyzed?
    • 1) ATP + H20 <--> ADP + Pi + H+
    • 2) ATP + H2O <--> AMP + PPi + H2O
  2. What is the principle donor of free energy in biological systems?
  3. What is the half-life of ATP in an active cell?
    30 seconds
  4. List in order of decreasing energy transfer potential: Creatine phosphate, G3P, Glucose, ATP
    Creatine phosphate, ATP, Glucose, G3P
  5. What are the roles of NADH and FADH2? What kinds of reactions do they assist with?
    Electron carriers, Redox
  6. What are 2 ways that a molecule can be oxidized?
    • 1) Loss of H
    • 2)Gain of O
  7. Why is oxygen considered to be an ozidizing agent?
    It causes species to lose e- and become more oxidized.
  8. What are the three species of electron carriers?
    Pyrimidine nucleotides, Flavins, Quinones
  9. What do NAD and FAD stand for?
    Nicotinamide Adenine dinucleotide and Flavin Adenine dinucleotide
  10. What is this? Image Upload
  11. What is this? Image Upload
  12. Which OH group in the adenine nucleotide can be phosphorylated to make NADP?
    The 2' OH group
  13. What is this? Image Upload
    A Quinone
  14. Which are oxidizing, and which are reducing? NAD+ and NADH, FAD or FADH2
    • NAD+ and FAD are OXIDIZING, want e-.
    • NADH and FADH2 are reducing, give e-.
  15. How many equivalents of H do FAD and NAD+ accomodate?
    • FAD accomodates 2 equivalents, the hydride and the proton ions.
    • NAD+ accomodates 1 in the form of a hydride.
  16. Why does biosynthesis require reducing agents?
    Biosynthesis; the formation of biomolecules from oxidized starting materials requires reducing agents NADH, NADPH and FADH2 because the starting materials are more oxidized than the products.
  17. Where are NADH and NADPH used?
    a) NADH ---> used primarily for the generation of ATP

    b) NADPH ---> used almost exclusively for biosynthesis reactions where reduction or oxidation is required.
  18. What are coenzymes?
    Coenzymes are derivatives of vitamins and other molecules that are required for the functional activity of an enzyme
  19. Which vitamin precursor molecules are NADH and FADH made from?
    • a) NADH is made from Niacin (nicotinate or nicotinic acid)
    • b) FADH2 is made from riboflavin or vitamin B2
  20. What is coenzyme A? What is it's structure?
    CoA is derived from the vitamin pantothenate and is the universal carrier of acyl groups of varying lengths.

    The common theme of a ribose + base Adenine Nucleotide (phosphates included). The thiol reactive end forms a thioester bond with the carboxylic acid portion on the acyl group.
  21. Is the delta G for hydrolysis of Acyl CoA favorable (-) or unfavorable? (+)?
    delta G for hydrolysis is favorable (-).

    *AcylCoA + H2O <--------> Acyl + CoA + H+

    (Equilibrium lies to the right standard conditions) In other words, it takes energy to form the AcylCoA species.
  22. How is biotin unique?
    • biotin is unique in the fact that this molecule can use CO2 to add carbon onto a biomolecule. Activation of biotin requires energy.
    • Need for biotin is demonstrated in the proteins found in egg whites which sequester or bind biotin (avidin, streptavidin) unsuable biotin inhibits microbial growth
  23. What is Coenzyme Q?
    Ubiquinone is an electron carrier which serves in the electron transport chain - leads to the net synthesis of ATP
  24. What is PLP and what is it derived from?
    Pyridoxylphosphate. Derived from pyridoxine (B6) and used in several areas of metabolism.
  25. What is TPP and what is it derived from>
    Thiaminpyrophosphate. Derived from Thiamin (B1)
  26. What are the three ways that metabolism is regulated?
    De novo synthesis, Activation/Inhibition, Compartmentalization
  27. What is De novo synthesis?
    control of enzymatic function lies in the expression of the gene.
  28. What are four ways to control metabolism by Activation/Inhibition
    Enzymatic activity controlled by cellular mediators. (Allosteric, feedback, zymogens, phosphorylation)
  29. What is a zymogen?
    An enzyme produced in an inactive state. Activation involves a complex series of signaling events culminating in cleavage of inhibitory protein subinits by proteases.
  30. What is an example of compartmentalization?
    All enzymes required for fatty acid catabolism are in the mitochondria. Enzymes for fatty acid synthesis are in the cytosol.
  31. What is the difference between a catabolic and an anabolic process?
    • Catabolic = degradative (exergonic)
    • Anabolic = synthesis (endergonic)
  32. What is the energy charge of a cell?
    The ratio of usable energy to total forms of available and used energy.
  33. What is the charge of the cell when [ATP]= 0?
    When [ATP] = [ADP]?
    When [ATP]is 4 - 5x greater than [ADP]?
    What is the actual energy charge of most cells?
    • -0.5 (death),
    • 0.75,
    • .9 (make fat).
    • 0.75-0.90.
Card Set:
Intro to metabolism.txt
2011-12-04 06:14:32
Intro Metabolism

WSU Biochem 3070 Ch.9
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