BITSAT 2024 Shift 1 Paper

A tetrapeptide consists of four amino acids: alanine, serine, glycine, and valine. Given that alanine is the C-terminal amino acid and the N-terminal amino acid must be chiral, we cannot use glycine at the N-terminal position because it is achiral. This means the N-terminal amino acid can be either valine or serine, as both are chiral.
Considering these constraints, we have the following possible sequences for the tetrapeptide:
Val-Gly-Ser-Ala
Val-Ser-Gly-Ala
Ser-Gly-Val-Ala
Ser-Val-Gly-Ala
These sequences respect the condition of having a chiral N-terminal amino acid, with alanine fixed as the C-terminal amino acid.