1 - VARIABLE ON ENZYME CONTROLLED REACTION

• AIM?

  effect of named variable on rate of enzyme-controlled reaction

  -> pH/ temperature
• INDEPENDENT VARIABLE?

  pH/ temperature
• VERSIONS OF EXPERIMENT?

  H2O2 -(catalase in yeast)-> water + oxygen

  • DV: volume of oxygen produced in 1 minute (cm cubed/ dm cubed)

  Casein -(trypsin protease)-> smaller peptides

  • white polypeptide to colourless
  • DV: time taken for solution to turn colourless (s) using colorimeter
• CONTROL VARIABLES?

  • temperature/ pH
  • concentration of substrate/ enzyme
  • enzyme type
  • volume of substrate/ enzyme
• CREATING A CONTROL?

  • boil enzyme so it denatures
  • replace enzyme with same volume of distilled water
• HOW TO CALCULATE INITIAL RATE OF REACTION?

  gradient of tangent at t = 0
• HOW TO CALCULATE RATE OF REACTION?

  1 / time
• RISK?

  enzymes can cause allergic reaction/ irritant

  -> avoid contact with skin/ eyes, wear goggles
• HOW DOES INCREASED TEMPERATURE AFFECT ENZYME ACTIVITY?

  • increased temperature, increases activity
  • substrate and enzyme have more KE
  • more successful collisions
• HOW DOES TEMPERATURE DENATURE ENZYMES?

  causes hydrogen bonds to break
• HOW DOES pH DENATURE ENZYMES?

  disrupts ionic bonds
• HOW DOES THE E-S COMPLEX CAUSE PRODUCTS TO FORM?

  puts pressure on substrate causing bonds to break/ new bonds to form