Question

Glycine (C2H5NO2) is added to a growing peptide chain containing methionine (C5H11NO2S) and alanine (C3H7NO2). Which of the following peptide chain orientations best displays the growing chain and peptide bond between the amino acids?

Answer 1

The growing peptide chain with the amino acids methionine, glycine, and alanine is best displayed in the orientation Methionine-Glycine-Alanine.

Step-by-step explanation:

The growing peptide chain with the amino acids methionine, glycine, and alanine can be best displayed in the orientation Methionine-Glycine-Alanine. This arrangement ensures that the free amine group (NH2) of methionine is on the left end of the chain, and the free carboxyl group (COOH) of alanine is on the right end of the chain.

The peptide bond between the amino acids is formed through a dehydration synthesis reaction, where the carboxyl group of one amino acid is linked to the amino group of the other amino acid, releasing a water molecule. It is important to follow the convention of listing the amino acid sequence with the free amine group on the left and the free carboxyl group on the right.