One of the following is nonessential amino acid:
## **Core Concept**
Amino acids are classified into essential and nonessential amino acids based on their synthesis in the human body. Essential amino acids cannot be synthesized by the body and must be obtained through diet, whereas nonessential amino acids can be synthesized by the body.
## **Why the Correct Answer is Right**
The correct answer, , is a nonessential amino acid because it can be synthesized in the human body through the transamination of α-ketoglutarate. This process involves the transfer of an amino group from an amino acid to a keto acid, which in this case results in the formation of glutamate (glutamic acid) from α-ketoglutarate.
## **Why Each Wrong Option is Incorrect**
* **Option A:** is an essential amino acid. It cannot be synthesized by the human body and must be obtained through dietary sources.
* **Option B:** is an essential amino acid. It is necessary for protein synthesis and cannot be produced by the body in sufficient amounts.
* **Option D:** is an essential amino acid. It plays a critical role in various bodily functions, including the synthesis of proteins and other molecules.
## **Clinical Pearl / High-Yield Fact**
Remember that nonessential amino acids can be synthesized by the body, but this does not mean they are not important. Glutamate, for example, serves as a critical neurotransmitter and a key intermediate in nitrogen metabolism.
## **Correct Answer:** . Glutamic acid