Key Area 1.6: Essay Questions

Question 1

Give an account of enzyme action and of the effects of competitive and non competitive inhibition

Answer 1

• enzyme activity depends on the flexible/ dynamic shape of enzyme molecules
• substrate has an affinity for the active site
• induced fit
• active site orientates the reactants
• enzymes lower the activation energy
• products have a low affinity for the active site
• substrate and product concentrations affect the direction and rate of reactions or increasing the substrate concentration increases the rate of reaction
• enzymes may af in groups
• competitive inhibition: the inhibitor resembles the substrate molecule, inhibition is reduced by increase in substrate concentration
• non competitive inhibition: the shape of the active site is changed, product/ feedback inhibition