What Are Enzymes?

• Catalyst


  • A substance that can speed up a chemical reaction without itself being chemically changed at the end of the reaction.
  • In living organisms, the catalysts are called enzymes.
• Activation Energy


  • energy needed for a chemical reaction to be activated

  
• Enzymes

  • Enzymes are proteins that function as biological catalysts. They catalyse or speed up the rate of chemical reactions.
  • They remain chemically unchanged at the end of the reaction.
  • they are specific in action

  
• Enzyme-catalysed Chemical Reactions in Living Organisms

  • Building up complex substances:

  – Protein synthesis

  – Photosynthesis

  • Breaking down complex substances:

  – Respiration

  – Decomposition of hydrogen peroxide