Factors affecting rate of reaction

• Describe the effect of substrate concentration on rate of reaction?

  • As the substrate concentration increases the rate of reaction increases as there will be more substrate molecules to fill the enzyme's active sites
  • There will be more frequent collisions, so there will be more formation of enzyme-substrate complexes
  • At some point a saturation point will be reached when all the enzyme's active sites are occupied with substrate molecules
  • Th addition of more substrate molecules will not effect the rate of reaction, at this point the reaction is proceeding as fast as possible referred to the Vmax
• What is the only way to speed up the rate of reaction when all the enzyme's active sites are occupied with substrate molecules?

  Increasing the enzyme concentration
• Describe the effect of temperature on rate of reaction?

  • Low temperature --> slower rate of reaction ---> less amount of kinetic energy ---> less collisions ---> reduced formation of enzyme-substrate complexes
  • Increasing temperature ---> increases rate of reactions ---> more kinetic energy --> more frequent collisions ---> increasing formation of enzyme-substrate complexes
  • High temperature --> hydrogen bond break within the protein --> protein unravels and denatures ---> active site loses shape --> unable to bind to their substrate ---> decreasing rate of reaction
• Describe the effect of pH on the rate of reaction?

  • Each enzyme has its optimum pH at which it works best depending on the environment which it operates in
  • Deviations from the optimum levels can cause the enzyme's structure to change reducing its ability to bind to its substrate, slowing down the rate of reaction