The correct answer is option 4. Valine.
Amino acids are the building blocks of proteins, and they are classified into two main categories: essential amino acids and non-essential amino acids. Essential amino acids are those that the human body cannot synthesize on its own, and therefore, they must be obtained from the diet.
Now, let us examine each option:
1. Glycine:
Glycine is a non-essential amino acid because the human body has the ability to synthesize it. It is the simplest amino acid, with a hydrogen atom as its side chain.
2. Alanine:
Alanine is also a non-essential amino acid. The body can synthesize alanine from other sources and does not necessarily rely on dietary intake.
3. Glutamine:
Glutamine is considered a non-essential amino acid. The body has the capacity to produce glutamine as it is needed.
4. Valine:
Valine, on the other hand, is an essential amino acid. It falls into the category of essential amino acids because the human body cannot synthesize it internally. Therefore, it must be obtained from the diet, particularly from protein-rich foods.
In summary, among the given options, only Valine is an essential amino acid. The body cannot produce valine on its own, making it crucial to include valine-containing foods in the diet to meet the body's requirements for protein synthesis and other physiological functions. |
