The non-essential amino acid among the following is:

Concept:

• Amino acids are biological molecules which combines to form proteins.
• Protein is essential for the overall growth of the living organisms, which helps for the growth, repair of the tissues and for various body functions.
• Amino acid are of two types, essential amino acid and non-essential amino acid.
• Essential amino acid, these amino acids can not be synthesized by the body, hence, must be taken from various sources.
• The essential amino acids are histidine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
• Non-essential amino acid, are produced by the body and need not be taken from outside.
• The non-essential amino acids are alanine, arginine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

Hence, the correct option is 3) Alanine.