Video Transcript
Order the following structures from the smallest to the largest in size: polypeptide chain, amino acid, protein. (A) Amino acid, polypeptide chain, protein. (B) Polypeptide chain, amino acid, protein. (C) Amino acid, protein, polypeptide chain. Or (D) polypeptide chain, protein, amino acid.
This question asks us to order these three structures from smallest to largest in size. Let’s start with the smallest of these structures, the amino acid. The amino acid pictured here is glycine. This is one out of 20 common amino acids that can be joined together during the process of translation to form a polypeptide. A polypeptide is a chain of amino acids that are linked by peptide bonds. The specific chemical nature of these amino acids can cause this linear polypeptide chain to fold onto itself to form a specific shape with a specific function. This is called the protein. Therefore, the correct order in terms of size is (A), amino acid, polypeptide chain, protein.
