For conversion of asparatate to asparagine, nitrogen comes from –
**Core Concept**
The conversion of aspartate to asparagine involves an amino group transfer, a fundamental process in amino acid metabolism. This reaction is crucial for the synthesis of asparagine, an important amino acid in various biological processes. The enzyme responsible for this conversion is asparagine synthetase.
**Why the Correct Answer is Right**
The correct answer involves the identification of the nitrogen source for this conversion. In the reaction catalyzed by asparagine synthetase, the nitrogen atom comes from **ammonia (NH3)** or more accurately, from the amide group of **glutamine**, which serves as the nitrogen donor. This process is vital for the biosynthesis of asparagine.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not specify the correct nitrogen source.
**Option B:** Incorrect as it is not directly related to the nitrogen source for asparagine synthesis.
**Option C:** Incorrect because, although glutamine is involved, the question seems to seek the direct nitrogen source, which could be misunderstood without specifying glutamine's role.
**Clinical Pearl / High-Yield Fact**
Remember, asparagine synthetase uses **glutamine** as a nitrogen source to convert aspartate into asparagine, highlighting the importance of glutamine in nitrogen metabolism and transfer reactions.
**Correct Answer:** D. Glutamine