Define the following as related to proteins (i) Peptide linkage (ii) Primary structure (iii) Denaturation.
Proteins are linear chains of amino acids linked by peptide bonds. Peptide linkage refers to the bond that connects amino acids together to form polypeptides.
The sequence of amino acids i.e., the positional information in a protein – which is the first amino acid, which is second, and so on – is called the primary structure of a protein. The first amino acid is called the N-terminal amino acid and the last amino acid is called the C-terminal amino acid.
When the secondary or tertiary structure of proteins get disturbed on change of pH or temperature and they are not able to perform their functions, this is called denaturation of proteins.
Explanation
This question tests understanding of basic protein terminology from NCERT Class 12 Chemistry Chapter 14 (Biomolecules). All three definitions are directly sourced from the textbook. Peptide linkage refers to the covalent bond connecting amino acids. Primary structure describes the linear sequence of amino acids. Denaturation explains the loss of protein structure and function due to environmental changes.