Problem Set 15. Serine, Glycine and Threonine


1. The metabolism of serine and glycine requires the coenzyme, tetrahydrofolic acid (FH4). The structure of tetrahydrofolic acid is:

2. Threonine does not undergo either transamination or decarboxylation directly.

3. The structures of these amino acids are:




Answer the following questions:

1. In principal, pyridoxal phosphate (PALP) can catalyze four different reactions of serine. The structure of PALP is:

Predict the products of these reactions.

2. Look for the enzymes that catalyze the PALP reactions you wrote. What do you conclude.

3.  The structure of phosphatidic acid is:

What is the product of the phosphatidylserine decarboxylase reaction?

4.  The one carbon compound formed by a retroaldol reacts with N10 of tetrahydrofolic acid. Predict the final product.

5.  Construct a metabolic map for serine ( including enzymes). What conclusions can you draw.

6. Predict the products of transamination and decarboxylation.

7. Construct a metabolic map for glycine metabolism. What conclusions can you draw?

8. PALP catalyzes two reactions with threonine. Predict the products.

9. Threonine dehydrogenase  exists , but it does not oxidize the amino group. Predict the products.

10. Construct a  metabolic map for threonine. What does the  map tell you?


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