Question

The transamination reaction between oxaloacetate and alanine leads to formation of pyruvate and ____ acid.

• A. Malic
• B. Glutamic
• C. Fumaric
• D. Aspartic

Hint:

Alanine loses its amino group to become pyruvate, and that amino group goes onto oxaloacetate.

Answer 1

The Correct Option is D

Step 1: Transamination is the transfer of an amino group from one amino acid to a keto acid, forming a new amino acid and a new keto acid, without releasing free ammonia.

Step 2: Here alanine is an amino acid and oxaloacetate is a keto acid. Alanine donates its amino group to oxaloacetate. Removing the amino group from alanine converts it into pyruvate, while oxaloacetate gains that amino group and becomes aspartate.

Step 3: Malic and fumaric acids are intermediates of the citric acid cycle unrelated to this particular amino transfer, and glutamic acid would result if the acceptor keto acid were alpha ketoglutarate instead of oxaloacetate.