Co-Authored By:
Pepsin is most active in acidic environments between 37 °C and 42 °C. Accordingly, its primary site of synthesis and activity is in the stomach (pH 1.5 to 2).
Then, what is the optimum pH of pepsin?
about 1.5
why does pepsin have a low pH?
The reason pepsin functions best at pH 2 is because the carboxylic acid group on the amino acid in the enzyme's active site must be in its protonated state, meaning bound to a hydrogen atom. At low pH the carboxylic acid group is protonated, which allows it to catalyze the chemical reaction of breaking chemical bonds.
pepsin contain the aromatic amino acid residues tyrosine or phenylalanine. In the most sensitive substrates, tyrosine is combined with glutamic acid.