A polypeptide chain has a free amino group at one end. That end is called the:

1. Amino acids join through peptide bonds to form a chain with two distinct ends. 2. One end still carries a free amino group and the other a free carboxyl group. 3. The end with the free amino group is the N terminal, or amino terminal. 4. The opposite end is the C terminal, also called the carboxyl terminal. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 3 'Biological Macromolecules', sections 3.1-3.5_