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Reading Guide, Stryer Short Course, Chapter 28
1. List the three stages of fatty acid synthesis.
2. Where in the cell does FA synthesis take place? How does acetyl CoA get there?
3. What is the role of citrate lyase? What hormone leads to its activation?
4. The synthesis of palmitate requires _____ molecules of NADPH as well as __________.
5. The shuttle that returns oxaloacetate back to the matrix also produces _____________, which
is needed in fatty acid synthesis.
6. Draw the product of the reaction catalyzed by acetyl CA carboxylase. Which cofactor does it
require? How much ATP is required? Why is this the regulatory enzyme for fatty acid synthesis?
7. In the first step of fatty acid synthesis, malonyl Coa condenses with acetyl CoA and releases
the CO2 that had just been put on by acetyl CoA carboxylase. Why was the carboxylation done
simply to be decarboxylated in the next step?
8. What reducing cofactor is needed in fatty acid synthesis? How many are consumed in each
round of elongation?
9. Write the net reaction that transforms 8 acetyl CoA into palmitate.
10. What is the main difference between the enzymes of bacteria fatty acid synthesis and
eukaryotic fatty acid synthesis? What is the advantage in the eukaryotic process?
11. Why is fatty acid synthesis a potential therapeutic target for cancers?
12. Which of the following fatty acids can be synthesized from palmitate (16:0) by human cells?
(18:0), (18:1 cis-9), (16:1 cis-9), (18:2 cis-9, 12), (18:3 cis-9, 12, 15)
13. Fatty acid synthesis is regulated at the enzyme ____________________. How do each of
these molecules effect this enzyme? AMP, citrate, palmitoyl CoA.
14. Fatty acid degradation is regulated at what site? What is the effect of malonyl CoA on this
protein?
15. The hormone _____________ stimulates fatty acid synthesis by activating the enzyme
_______________, while __________ and ____________ have the opposite effect.
16. Metabolism of ethanol in the liver leads to the production of high concentrations of what
reducing cofactor? Production of large amounts of acetyl CoA then leads to formation of
_________________ and _________________, which are detrimental to the liver.