factors affecting

• Factors that affect enzyme activity

  • Temperature
  • pH of the solution
  • Concentration of the substrate
  • Concentration of the enzyme
  • Presence of inhibitors
  • Presence of activators
• Effect of temperature on enzyme activity

  1. As temperature increases, rate of reaction increases

  2. Rate reaches optimal temperature

  3. Rate drops sharply due to protein denaturation
• Optimal temperature


  Temperature at which rate of reaction is highest
• Most enzymes are protein-based catalysts
• Protein denaturation


  Enzyme loses shape and function
• Effect of pH on enzyme activity

  1. As pH changes, rate of reaction changes

  2. Enzymes have optimal pH range

  3. Some enzymes like pepsin have lower optimal pH
• Increasing substrate concentration


  Increases enzyme activity and rate of reaction
• Increasing enzyme concentration


  Increases rate of reaction
• Increasing substrate concentration beyond optimal

  Rate of reaction levels off due to limited enzyme molecules
• Inhibitors


  Decrease enzyme activity and rate of reaction
• Activators


  Enhance enzyme activity and increase rate of reaction
• Types of inhibitors


  • Competitive inhibitors - compete with substrate for active site
  • Non-competitive inhibitors - bind to allosteric site, change enzyme shape
• Competitive inhibitor prevents substrate from binding to active site
• Non-competitive inhibitor binds to allosteric site, changes enzyme shape so substrate can't bind