enzyme mechanisms

• Enzymes are globular proteins
• Enzymes are catalysts
• Enzymes can catalyse intracellular and extracellular reactions
• Catalysts lower the activation energy for reactions. This means more particles with lower energy can have successful collisions

  
• Metabolism - The sum of all the different reactions and reaction pathways happening in a cell or organism
• catalyst - Something that speeds up a reaction without being used up
• anabolic - Chemical reactions that are required for growth and which build up
• catabolic - Chemical reactions that break down
• Enzyme - amylase

  Substrate - starch

  Product - maltose

  Where Found? - saliva and small intestine

  Intracellular or Extracellular? - extracellular
• Enzyme - catalase

  Substrate - hydrogen peroxide

  Product - oxygen and water

  Where Found? - plant and animal tissues

  Intracellular or Extracellular? - intracellular
• Enzyme - trypsin

  Substrate - proteins

  Product - smaller peptides

  Where Found? - small intestine

  Intracellular or Extracellular? - extracellular
• Enzyme - maltase

  Substrate - maltose

  Product - glucose

  Where Found? - small intestine

  Intracellular or Extracellular? - extracellular
• 1. substrate
  2. enzyme
  3. enzyme substrate complex
  4. products
  5. active site

  
• There is a newer theory known as the induced fit theory. This suggests that the active site of the enzyme changes slightly as the substrate enters (Enzyme specificity depends on the tertiary structure of its active site)

  
• • Enzymes are proteins which speed up the rate of biological reactions. They form an enzyme - substrate complex by binding to their substrate at a site known as the active site
  • This site has a specific shape created by the tertiary structure of the protein molecule. This means that each enzyme can bind to only one type of substrate molecule.
  • This is explained by the lock and key hypothesis.
• • In an alternative hypothesis, the binding site changes shape to fit more closely around the substrate molecule. This is called the induced fit hypothesis.
  • This hypothesis can help to explain how enzymes enable reactions to occur at lower temperatures by reducing the activation energy required for the reaction to occur.