Defines the following as related to proteins:
(i)Peptide linkage, (ii)Primary structure
(iii)Denaturation

Explanation

(i) Peptide linkage : Peptide linkage is an amide linkage formed between `-COOH` group of one `alpha`-amino acid and `-NH_(2)` group of other `alpha`- amino acid by loss of a molecule of water.
For example :

Primary structure : The specific sequence is which the various `alpha`amino acid present in a protein and linked to one another is called its primary structure.
(iii) Denaturation : When a protein is subjected to physical changes such as change in temperature, PH. etc., cleavage of hydrogen bonds, unfolding of protein molecule occurs and it loses its biological activity. This loss of biological activity is called denaturation.