Question

Which one of the following structures represents the peptide chain

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

To determine which structure represents a peptide chain, we first need to understand what constitutes a peptide chain. A peptide chain is composed of amino acids linked together by peptide bonds. A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of the next amino acid, releasing a molecule of water (a condensation reaction).

The images provided in the options represent different chemical structures. Let's examine each option to identify the characteristics of a peptide chain:

1. In the first image option, we observe that the structure does not display the typical peptide bond linkage between amino acids.
2. The second image option illustrates the linkage with repeated -CO-NH- units, indicating the presence of peptide bonds. This matches the molecular structure characteristic of a peptide chain.
3. The third image option lacks continuity through peptide bonds, failing to form a consistent chain of amino acid residues.
4. The fourth image option also does not display a continuous sequence of peptide bonds connecting multiple amino acids.

Based on the above analysis, the correct answer is the second image, which shows a consistent chain of amino acids with peptide bonds, effectively representing a peptide chain structure.

In conclusion, a peptide chain is characterized by the repetitive structure of peptide bonds linking the amino acids, as seen in the correct option. Peptide chains form the backbones of proteins, defining their primary structure through sequences of various amino acids.