Which structure shows part of a peptide link in a protein? A C || O C || O H B C || O C H || N O C C || O C || C O D C || O C || N H - AQA - A-Level Chemistry - Question 29 - 2019 - Paper 3

To determine which structure exhibits a peptide link, it is crucial to identify the amide bond formation between amino acids. A peptide link consists of a carbonyl group (C=O) bonded to a nitrogen atom (N) from another amino acid. The correct answer would be the option presenting this characteristic. In this case, structure D showcases the amide bond:

$ext{C} - ext{O}$ $ext{C} - ext{N}$ $ext{H}$

Thus, the correct structure that indicates part of a peptide link is option D.