Amino acids join to form which structures?

• A. Polypeptides and proteins
• B. Nucleic acids
• C. Lipids
• D. Carbohydrates

Answer: (A)

Amino acids link together through peptide bonds to form polypeptide chains, and these chains fold into functional proteins. The sequence of amino acids determines how the chain folds because the side groups interact in specific ways, giving the protein its shape and function. Some proteins consist of multiple polypeptide chains that come together to form a larger, final protein structure. Hence, amino acids join to form polypeptides and proteins.

Nucleic acids are built from nucleotides, lipids from glycerol and fatty acids, and carbohydrates from monosaccharides, so those options don’t reflect what amino acids specifically build.