Factors affecting enzyme action

Q: Why does an increase in temperature increase the rate of reaction?

• Enzymes work more effectively
  
  
• Molecules move faster - so have more collisions
  
  
• Colliding with more force
  

Q: Why do enzymes stop working if the temperature is too hot?

• Their shape changes - they denature
  
  
• The reacting molecules will not fit into the active site

Q: Why does the pH have to be 'right' for the reaction to go well?

• Enzymes work best in a narrow pH range
  
  
• If it varies too much then they might denature