Amino acid Metabolism 2 C483 Spring 2013

1. Arginine is biosynthesized from this precursor: A)Pyruvate B)Oxaloacetate C)  -ketoglutarate D)3-phosphoglycerate 2. A Roundup Ready plant is one that has been genetically modified so that an enzyme (EPSP synthase) can no longer bind to the active ingredient (glyphosphate) which is a competitive inhibitor of A) shikimate (in the aromatic amino acid pathway). B) tryptophan. C) lysine. D) phosphoenolpyruvate (PEP). 3. The conversion of tetrahydrofolate to methylene tetrahydrofolate is coupled to which amino acid conversion? A) serine → glycine B) glutamate → gglycine C) serine → threonine D) glycine → alanine

4. If an amino acid is glucogenic, it will not be degraded to ________. A) pyruvate B) glutamate C) fumarate D) acetoacetate 5. T/F It is possible for an amino acid to be both ketogenic and glucogenic.

Overview of Biosynthesis Common intermediates

Recognizing Carbon Chains Name these AA precursor molecules, and match them to the AA that is produced: alanine, serine, glutamate, asparagine

Essential Amino Acids Definition of “essential” Ambiguity with cysteine and tyrosine Arginine is essential in some mammals and in some development stages

Aromatic AA Biosynthesis

Catabolism of carbon chain

Overview of Catabolism Ketogenic vs Glucogenic amino acids Utilization of branched AA in muscle Know particular cases – Deamination: Ala, Asp, Asn, Glu, Gln – Glucogenic: Arg – Ketogenic: Leu – Both: Ile – Cofactor synthesis: serine Importance of PLP in amino acid processing

Ketogenic and Glucogenic

Answers 1.C 2.D 3.A 4.D 5.T