factors affecting enzymes

• Temperature


  If too low, not enough kinetic energy for successful collisions between enzyme active sites and substrate. If too high, enzyme denatures and active site changes shape.
• pH


  If too high or too low, enzyme will denature. Hydrogen ions or OH- ions interfere with charges in amino acids, breaking ionic and hydrogen bonds and changing active site shape.
• Substrate concentration


  At low concentrations, substrate is the limiting factor. As concentration increases, rate increases until active sites become saturated and enzyme concentration becomes the limiting factor.
• Enzyme concentration


  At low concentrations, enzyme is the limiting factor. As concentration increases, rate increases until substrate becomes the limiting factor and active sites are not fully utilized.
• Competitive inhibitor


  Molecule that binds to active site, preventing substrate from binding. Can be outcompeted by high substrate concentrations.
• Non-competitive inhibitor


  Binds to enzyme away from active site, changing its shape and preventing substrate binding.
• Competitive inhibitor effect on rate

  Lowers rate until high substrate concentrations can outcompete inhibitor.
• Non-competitive inhibitor effect on rate

  Lowers rate to a plateau, as active site shape is permanently altered.
• Inhibitors are molecules that bind to enzymes and prevent them from functioning.