Q. Which of the following are classified as essential amino acids in humans?

1. Lysine
2. Leucine
3. Tryptophan

Select the correct option from the codes given below:
Answer: 1, 2 & 3
Notes: Lysine, leucine, and tryptophan are among the nine essential amino acids for humans. Essential amino acids cannot be synthesized by the body and must be obtained from the diet. All three mentioned—lysine, leucine, and tryptophan—meet this criterion and are crucial for protein synthesis and various metabolic functions.