Enzymes are affected by pH in two ways. In the first instance, electrostatic charges on groups at the enzymes active sites are modified, and, secondly those charges are responsible for holding the molecular shape and active configuration may be disrupted. Both of the above factors have significant influence on the catalytic properties of the enzymes. These effects are illustrated using the enzyme Amylase and Invertase. Suitable for A-level or tertiary level students. Experiments included:. Effect of pH on Invertase activity. Effect of extremes of pH on stability of invertase. Effect of extremes of pH on stability of Amylase. Kit contains:. Sucrose. Potassium Sodium Tartarate. Sodium Hydroxide - 0.5M. Amylase Working Solution. Invertase 'Bioinvert'. Hydrochloric Acid - 0.5M. 3,5-Dinitrosalicylic Acid. Starch. 1% Iodine Solution. Buffer concentrate - pH7. Buffer concentrate pH6.5. Buffer concentrate pH2.8. Universal Indicator Papers. Sufficient materials included for 10 students/student groups.
