Amino acid Metabolism 2

Amino acid Metabolism 2

C483 Spring 2013

1. Arginine is biosynthesized from this precursor:A) PyruvateB) OxaloacetateC) a-ketoglutarateD) 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 ofA) 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 → glycineB) glutamate → gglycineC) serine → threonineD) 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

O

O

O

O

O

O

O

O

O

O

O

O

O

OO

O

OH

PO

O

O

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

NH

O

O

PO

O

O

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. C2. D3. A4. D5. T