Enzymes

• Induced fit model

  • Shape of active site of an enzyme is not exactly complementary to the substrate molecule
  • When the substrate collides with the enzyme the active site changes slightly to fit around the substrate
• Factors effecting enzyme rate of reaction

  Enzyme concentration

  Substrate concentration

  Temperature

  pH
• Competitive inhibition

  • Have similar shape to substrate molecules
  • Compete with substrate to bind to the active site
  • Block the active so the substrate cannot bind and no ES complexes formed
• Non-competitive inhibition

  • Do no bind to active site as have different shape to substrate so do not compete
  • Bind to allosteric site
  • Causes active site of the enzyme to change shape so is no longer complimentary to the substrate so no ES complexes formed