Stomach pepsin works best near pH 2; intestinal trypsin near pH 8. Why?
- A
All digestive enzymes function with equal catalytic efficiency across the full range of physiological pH values
- B
Random differences — physiological pH has essentially no real effect on the catalytic activity of these enzymes
- C
pH directly determines the rate of DNA replication occurring within the cells that secrete these two enzymes
- Dcheck_circle
Each enzyme's structure (and the protonation of active-site residues) is optimized for its physiological pH
Explanation
Enzymes evolve to function in their compartment. Outside its optimum, an enzyme's shape and ionization state are wrong for catalysis.