Insulin: A Natural Condensation Polymer of Amino Acids

Steps:

• Proteins like insulin form by linking amino acids via condensation reactions, eliminating water to create polymer chains, confirming statement 1.
• Insulin is produced biologically in the pancreas, not manufactured artificially, so statement 2 is false.
• Hydrolysis of insulin breaks peptide bonds to yield 51 amino acids of 20+ different types, not a single monomer, making statement 3 incorrect.
• The linkages in insulin are peptide bonds, a type of amide bond between carboxyl and amino groups, verifying statement 4.

Why C is correct:

• Proteins are defined as condensation polymers with amide (peptide) linkages, matching statements 1 and 4 exactly.

Why the others are wrong:

• A includes false statement 2 (insulin is natural, not synthetic).
• B includes false statement 3 (hydrolysis yields multiple monomers).
• D includes false statements 2 and 3.

Final answer: C