Final answer:
A propeptide may be found in the process of peptide synthesis. During peptide synthesis, amino acids are joined together to form a polypeptide chain. After protein synthesis, most proteins undergo post-translational modifications.
Step-by-step explanation:
A propeptide may be found in the process of peptide synthesis.
During peptide synthesis, amino acids are joined together to form a polypeptide chain. This chain is initially known as a propeptide. As more amino acids join the chain, it becomes a polypeptide. Each polypeptide has a free amino group at one end called the N terminal and a free carboxyl group at the other end called the C terminal.
It's important to note that a protein can be a single polypeptide or multiple polypeptides combined together. After protein synthesis, most proteins undergo post-translational modifications to become functional.