Which of the following is an essential amino acid?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Leucine
Amino acids that the body can synthesise are non-essential; those that cannot be synthesised in the body and must be obtained through the diet are essential amino acids. Of the twenty amino acids in proteins, ten are essential:
valine, leucine, isoleucine, arginine, lysine, threonine, methionine, phenylalanine, tryptophan, histidine
Leucine is in this list, so it is the essential amino acid.
NCERT (2026-27 edition):
Classification of Amino Acids
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| – | – | – | 12-06 S2 25-05 S3 | – |