C485 Final Exam Fall ‘14
Name______
Legible please!
Do not use acronyms. Use structures whenever they are asked for, or appropriate. Your explanations should be brief. Overly lengthy answers with irrelevant or erroneous material will receive deductions. GOOD LUCK
1. (15pts) The metabolism of xenobiotics usually takes place in phases. Show the typical transformations that take place in these phases (you must show the specific change in a molecule using structures). Where do these reactions usually take place? Show the mechanism by which the most common phase one modification takes place.
2. (12pts) The intake of large amounts of alcohol has a profound effect on a number of the major metabolic pathways. Explain what this effect is and explain how this happens.
3. (14pts) Explain the environmental and cellular mechanisms used to control Rubisco. Explain the rationale behind these control elements. Sketch the active site of the enzyme (to the degree you are capable) noting any particular cofactors and unusual features of the active site. Draw the mechanism of the rubisco-catalyzed reaction in full. You MUST use structure and arrows as appropriate.
4. (12 pts) Show the two methods by which cells generate most of their NADPH.
5. (12 pts) Cells respond to changes in their environment on a very fast time scale (< one second) and on a slower time scale ( > seconds). Explain how this occurs in muscle with respect glycogen breakdown. Make sure you show the entire sequence of events associated with regulation on the > second level.
6. (8 pts) There are two pathways leading from pregnenolone to androstenedione. There are then two pathways from androstenedione that lead to estradiol. Starting with pregnenolone, draw these pathways. Please use structures. (If you use names, you will get only 1/4 credit)
7. (16 pts) Starting with a C-11 saturated fatty acid, calculate the overall ATP yield if this molecule is processed down to a three carbon remnant. What is the remnant? How is it further metabolized into a compound that intersects a major metabolic pathway? Show the mechanism for the reactions used to metabolize this remnant.
8. (11 pts) Outline the major steps of a full photosynthetic cycle. Show what each major element is responsible for in terms of proton uptake and pumping, as well as the end products of the cycle.
9. (8 pts). Explain the difference between type 1 and type 2 diabetes. Explain likely molecular mechanisms for the cause of type 2 diabetes.
10. (6 pts) In which ways are fatty acid synthesis and breakdown different?
11. (10 pts) Phenylketonuria is a relatively uncommon enzymopathy. What enzymatic step is affected (draw it, or name the enzyme)? What is the outcome of this enzymopathy (on a chemical basis)? Draw the mechanism of this enzymatic step.
12. (12 pts) Outline the complete biosynthesis of leucine. Draw the mechanism of the first step in the pathway.
13. (24 pts) Consider an actively working muscle cell using branched chain amino acids to generate energy. Draw the pathways by which the cell breaks down these amino acids. How does the muscle cell rid itself of the resulting ammonia? Using full structures and reactions, show the fate of the nitrogen in the branched chain amino acids and show how it is eliminated from the body?
14. (10 pts) Outline the chemical steps involved in the biosynthesis of tyrosine in bacteria.
15. (18 pts) Outline the biosynthesis of CTP. Show all reactions, including products and starting materials. Show the synthesis of deoxy-CDP from CDP. Draw the mechanism of this reaction.
16. (8pts) Draw the mechanism for the conversion of S-adenosyl homocysteine to homocysteine and adenosine.
17. (16 pts) Outline the regeneration phase of the Calvin cycle. Which of these reactions are different from those found in the pentose phosphate pathway? Explain why these reactions are different and what goal is accomplished by having these reactions. Draw the mechanism of the reaction that transfers two carbon fragments.
18. (8 pts) Outline the biosynthesis of phosphatidyl choline, starting from ethanolamine, and diacylglycerol.
Point breakdown
Possible actual
1) 15 ______
2) 12 ______
3) 14 ______
4) 12 ______
5) 12 ______
6) 8 ______
7) 16 ______
8) 11 ______
9) 8 ______
10) 6 ______
Out of 114 ______
11) 10 ______
12) 12 ______
13) 24 ______
14) 10 ______
15) 18 ______
16) 8 ______
17) 16 ______
18) 8 ______
Out of 106 ______
Total Out of 220 ______