CH4 Enzymes

• Enzymes

  Biological catalysts that are protein in nature
• Enzymes


  • Speed up rate of biochemical reactions
  • Lower the activation energy of the reaction
  • Remain chemically unchanged at the end of the reaction

  
• Activation energy


  Minimum amount of energy to be attained by reactant particles for a chemical reaction to occur
• Lock and key hypothesis


  1. The shape of the substrate must be complementary to the shape of the active site of the enzyme

  2. The substrate can fit into the active site and form the enzyme-substrate complex

  3. The enzyme catalyses the reaction by lowering the activation energy of the reaction

  4. Enzymes are specific in action
• Enzymatic reaction / mode of action of enzymes

  • The substrate has a shape that is complementary to the shape of the active site of the enzyme
  • The substrate binds to the active site of the enzyme to form an enzyme-substrate complex
  • The enzyme lowers the activation energy of the biochemical reaction, hence increases the rate of the biochemical reaction
  • Products are formed and released from the active site of the enzyme
  • The enzyme remains chemically unchanged at the end of the chemical reaction and the active site is free to bind new substrates
• When temperature is low at (___)°C


  Rate of enzyme-catalysed reaction is low at (___) units because enzymes are inactive

  
• As temperature increases from (___)°C to (___)°C


  Rate of reaction increases gradually from (___) units to (___) units because as temperature increases, kinetic energy of enzyme and substrate molecules increases, causing probability of effective collision between enzyme and substrate molecules to increase, hence, frequency of formation of enzyme substrate-complex increases

  
• As temperature increases beyond the optimum temperature of (___)°C

  Rate of reaction decreases drastically to zero because high heat energy disrupted intramolecular bonds of the enzyme, causing a change in the shape of the active site, enzyme is denatured, and substrate can no longer fit into the active site of the enzyme

  
• Enzyme denatures at both low and high pH alike, since both extreme acidic and alkaline environments can disrupt intramolecular bonds