Enzymes

• Why do organisms need enzymes

  Chemical reactions are naturally very slow so enzymes speed it up
• Why don’t we increase the temp of our cells to increase the rate of chemical reactions

  Heating the cells require lots of energy

  High temperatures could damage our cells

  Higher temperatures would also speed up non-useful reactions
• Enzyme

  Biological catalysts
• Region where the enzyme binds to the substrate

  Active site
• Complex that’s formed when an enzyme binds to a substrate

  Enzyme-substrate complex
• Complementary

  It must be complementary to the active site of the enzyme
• Induced fit model of enzyme action

  States that in order for an enzyme to catalyse a reaction, the enzymes active site changes shape slightly as it binds to the substrate
• Factors that affect enzyme activity

  Temperature

  pH
• Optimum temperature

  The temperature that gives the highest enzyme activity
• Denatures

  Change in shape of an enzyme
• How can pH cause an enzyme to denature

  Can break the bonds holding the enzyme together

  Cause the active site to change shape

  Enzymes active site no longer complementary

  No longer form an enzyme-substrate complex