Enzymes are biological catalysts. They are found in living organisms and a catalyst changes the rate of a reaction but remains unchanged at the end of the reaction.

Each enzyme is specific for its substrate, which means that it only works with that substrate.


Active sites:

  • Enzymes have different active sites
  • They connect with substrates
  • Fit like a ‘lock and key’
  • These make an enzyme-substrate complex
  • Only specific enzymes breakdown specific substrates


Denatured enzymes:

  • Changing the temperature or pH of the enzyme meaning the active sight won’t fit the substrate
  • This would slow down the reaction