pH

• Affect of pH

  • H^+ ions/protons interfere with hydrogen and ionic bonds
  • Changing concentration
  • Affects 3D tertiary structure and active site
  • Changes reaction rate
  • Extreme: Irreversible shape change (denatured)
  • Experiment: Maintain pH by adding set pH buffer volume
  • Induced fit model:
  • Charged groups at active site
  • Important for binding substrate
  • Increasing H^+ ion concentration change active site charge
  • Reduce ESC formation
  • pH graph:
  • Symmetrical
  • Bell-shaped
  • Most intracellular enzymes are neutral (optimum pH = 7), not all