Question

Enter the common name of the α‑ketoacid resulting from the transamination of each amino acid.

1) alanine:

2) aspartate:

3) glutamate:

4) leucine:

5) phenylalanine:

6) tyrosine:

Answer 1

Transamination is a chemical reaction which transfers an amino group to a keto acid. These reactions are in general catalysed by the enzyme transaminases or amino transferases.

1) Alanine to pyruvate

2) Aspartate to Oxalo acetate

3) Glutamate to - Keto glutarate

4) Leucine to - Keto isocaproic acid

5) Phenylalanine to Phyenyl pyruvate

6) Tyrosine to 4- hydroxy phenyl pyruvate

Answer 2

Common Names of α-Ketoacids from Transamination

Amino Acid	α-Ketoacid Product (Common Name)	Structure
1) Alanine	Pyruvate	CH₃-CO-COOH
2) Aspartate	Oxaloacetate	HOOC-CO-CH₂-COOH
3) Glutamate	α-Ketoglutarate	HOOC-CO-CH₂-CH₂-COOH
4) Leucine	α-Ketoisocaproate	(CH₃)₂CH-CH₂-CO-COOH
5) Phenylalanine	Phenylpyruvate	C₆H₅-CH₂-CO-COOH
6) Tyrosine	4-Hydroxyphenylpyruvate	HO-C₆H₄-CH₂-CO-COOH

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Key Notes:

1. Transamination Reaction:

• Amino acid + α-ketoglutarate ↔ α-ketoacid + glutamate (catalyzed by aminotransferases).

• The amino group is transferred to α-ketoglutarate, forming glutamate.

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2. Examples:

• Alanine → Pyruvate: Central to glucose-alanine cycle.

• Glutamate → α-Ketoglutarate: Intermediate in the TCA cycle.

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3. Clinical Relevance:

• Elevated phenylpyruvate indicates phenylketonuria (PKU).

• Oxaloacetate is crucial for gluconeogenesis.