Million-Nasse’s reaction is specific for the amino acid:
**Core Concept**
Million-Nasse’s reaction is a chemical test used to identify specific amino acids. It is a colorimetric assay that relies on the oxidation of the amino acid by potassium periodate, resulting in a colored compound.
**Why the Correct Answer is Right**
The Million-Nasse’s reaction is specific for the amino acid **tyrosine**. This is because tyrosine contains a catechol group (-C6H4(OH)2-) that is oxidized by potassium periodate to form a quinone compound, resulting in a characteristic yellow color. This reaction is highly specific to tyrosine due to the unique structure of its side chain.
**Why Each Wrong Option is Incorrect**
* **Option A:** Glycine is the simplest amino acid, but it does not contain the catechol group necessary for the Million-Nasse’s reaction.
* **Option B:** Serine contains a hydroxyl group, but it is not oxidized by potassium periodate in the same way that tyrosine is.
* **Option C:** Phenylalanine is a non-polar amino acid that does not contain the catechol group necessary for the Million-Nasse’s reaction.
**Clinical Pearl / High-Yield Fact**
The Million-Nasse’s reaction is an important tool in biochemistry and clinical chemistry, particularly in the diagnosis of tyrosinemia, a genetic disorder characterized by elevated levels of tyrosine in the blood.
**Correct Answer:** D. Tyrosine