Final answer:
The term for a sequence of more than 40 amino acids is a polypeptide or protein.
Step-by-step explanation:
The general term for a larger number of amino acids, specifically more than 40 residues, is polypeptide or protein. Sequences of amino acids are written from the N-terminal to the C-terminal, and the order of amino acids is critical for the physiological activity of the peptide or protein. A chain of amino acids is known as a dipeptide if it has two units and a tripeptide if it has three. Chains of roughly 50 or more amino acids are generally referred to as proteins, although the terms polypeptide and protein are sometimes used interchangeably.