This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure & Function of Protein, Subject name: Biochemistry
The enzyme trypsin is specific for peptide bonds of: 
Select and explain. 
A. Basic amino acids, B. Acidic amino acids, C. Aromatic amino acids, D. Next to small amino acid residues
A: Basic amino acids
Answer: A: Basic amino acids 
Explanation: Ans. A. Basic amino acidsTrypsin is an endopeptidase which cleave protein chains at internal peptidebonds, but each preferentially hydrolyses bonds adjacent to a particular type of amino acid residue. Trypsin cuts just next to basic residues (lysine or arginine); chymotrypsin cuts next to aromatic residues (phenylalanine, tyrosine or tryptophan).