Chem. 454

NAME .

1. One of the last steps in alcohol breakdown involves conversion of acetate to acetyl CoA as shown. Propose an organic reaction mechanism to explain how this could occur. (don't forget to consider the involvement of ATP, hint, hint) (5 pts)

CH3COO- + ATP + CoASH Æ acetyl CoA + AMP + PPi

2. Why is malonyl-CoA used for fatty acid synthesis rather than acetyl CoA since thiolase (in ketone body formation) can run in the reverse direction? (5)

4. Discuss briefly some newer ideas about the causes of juvenile onset diabetes. (6)

6. Explain in as much detail as you can , using insulin stimulation as an example, how a single stimulus such as insulin can lead to both protein phosphorylation and dephosphorylation in a cell. A diagram of this cellular process will help.(10)

6. Explain why hypoglycemia (low blood and tissue glucose) encourages ketone body production. Don't forget the TCA cycle (hint, hint). (6)

7. Can fats be utilized for energy production (ATP) in the absence of a functional TCA cycle? Explain how (5)

8.Compare (and contrast) the intermediates, functions, etc.of the TCA cycle with the b-oxidation process. (6)

9. Explain biochemically how a relatively young person with chronic hyperglycemia (too much blood sugar) can have senile cataracts (characteristic of old people). (6)

10. Glycogen and fat are both mobilized by epinephrine and demobilized (synthesized) by the action of insulin. Explain the metabolic logic for this.(6)

BONUS:(2pts) Who was Rube Goldberg ? ß