Question
The number of possible tripeptides formed involving alanine (ala), glycine (gly) and valine (val), where no amino acid has been used more than once is:
JEE Main
Chemistry
Biomolecules
2026
JEE Main 2026 (24 January Shift 2)
JEE Main Chemistry Question (2026) — Solution
Options
- A. 3
- B. 8
- C. 6
- D. 4
Answer
C. 6
Step-by-step solution
For tripeptides with 3 different amino acids (ala, gly, val) where no amino acid is used more than once, each tripeptide must contain all three amino acids exactly once. The number of distinct tripeptides is the number of permutations of 3 amino acids = 3! = 6. These are: ala-gly-val, ala-val-gly, gly-ala-val, gly-val-ala, val-ala-gly, val-gly-ala.
Related: Chemistry — Biomolecules · All PYQ Banks