Key Concepts

• • Bell-shaped activity curves arise from the balance between increased kinetic energy and enzyme denaturation
• • Temperature above the optimum → hydrogen bonds and ionic bonds disrupted → denaturation
• • pH affects ionisation of R-groups in the active site — wrong pH distorts 3D shape
• • Pepsin (stomach) pH_opt ≈ 2; trypsin (intestine) pH_opt ≈ 8; salivary amylase pH_opt ≈ 7
• • Thermophile enzymes can function without denaturation at >70°C (e.g., Taq polymerase for PCR)