Aminopeptidase and carboxypeptidase are known as exopeptidases because they
A) remove amino acids from the ends of a peptide
B) remove nucleic acids from the ends of a nucleotide
C) remove fatty acids from the ends of a peptide
D) cause the breakdown of proteins into dipeptides and tripeptides
E) cleave peptide bonds within the interior of a protein

Question

Quizplus · Accepted Answer

Aminopeptidase and carboxypeptidase both act on the ends (or terminals) of a peptide chain. Aminopeptidase removes the amino-terminal residue from a peptide chain, while carboxypeptidase removes the carboxyl-terminal residue. Therefore, they are called exopeptidases, meaning that they cleave peptide bonds at the ends of a protein or peptide.

Aminopeptidase and Carboxypeptidase Are Known as Exopeptidases Because They