12.8 Peptides and Proteins

These are naturally occurring polymers in living systems. The polymers with molecular weights less than 10000 are termed as peptides and those with higher molecular weights are termed as proteins. The acid-catalyzed hydrolysis of peptides and proteins affords the constituent α-amino acids.

Scheme 1

12.8.1 Primary Structure of Protein

The primary structure of a protein describes the sequence of amino acids in the chain. Insulin is the first protein whose amino acid sequence was determined. Scheme 2 presents the primary structure of insulin.

Scheme 2. Primary Structure of Insulin