Final answer:
A linear polypeptide can give rise to a three-dimensional molecular machine through protein folding, where the chain of amino acids interact and fold to assume a specific shape.
Step-by-step explanation:
A linear polypeptide can give rise to a three-dimensional molecular machine through a process called protein folding. After a polypeptide chain is synthesized, it will undergo interactions among its amino acids, causing it to fold and assume a specific shape. These folded structures are essential for the function of proteins and can lead to the formation of complex molecular machines.