Question

Protein is a polymer made of

• A. carbohydrates
• B. amino acids
• C. nucleic acids
• D. carboxylic acids
• E. polycyclic aromatics

Hint:

Protein = Amino acids + peptide bonds → polypeptide chain → folded structure.

Answer 1

The Correct Option is B

Concept:
Proteins are biopolymers formed by the polymerization of amino acids. Amino acids are linked together by peptide bonds (-CONH-), forming long chains called polypeptides.

Step 1: Structure of amino acids
Each amino acid contains:
• Amino group (-NH$_2$)
• Carboxyl group (-COOH)
• Side chain (R-group)

Step 2: Formation of peptide bond
Two amino acids combine via condensation reaction: \[ \text{-COOH} + \text{-NH}_2 \rightarrow \text{-CONH-} + H_2O \] This bond is called a peptide bond.

Step 3: Formation of proteins

• Many amino acids → polypeptide chain
• Folding of chain → functional protein

Step 4: Analysis of options

• (A) Carbohydrates → polymers of sugars → incorrect
• (B) Amino acids → correct building blocks
• (C) Nucleic acids → DNA/RNA → incorrect
• (D) Carboxylic acids → not polymers here
• (E) Polycyclic aromatics → unrelated Final Conclusion:
Proteins are polymers of amino acids: \[ \boxed{(B)} \]