By Convention, Polypeptides are Read in Which Order

Question

By convention, polypeptides are read in which order?
A) N- to C-terminus
B) C- to N-terminus
C) 5' to 3'
D) 3' to 5'
E) smallest to largest amino acid by molecular weight

Accepted Answer

Polypeptides are read from the N-terminus (where the free amino group is) to the C-terminus (where the free carboxyl group is). This is because amino acids are linked together through peptide bonds between the carboxyl group of one amino acid and the amino group of another. Therefore, the sequence of the polypeptide is determined by the order of the amino acids from N-terminus to C-terminus.