enzymes

• Enzymes

  Biological catalysts that speed up a reaction by reducing its activation energy
• Enzymes

  • They are found in living organisms
  • They are biological catalysts
  • They speed up reactions by reducing activation energy
• catalysing a reaction

  1. Substrate binds to enzyme

  2. Enzyme lowers activation energy

  3. Reaction occurs

  4. Products are released
• Enzymes are specific, they can only catalyse reactions for a specific substrate
• Enzymes are not chemically changed during the reaction = only needed in small amounts
• Active site

  The specific region of an enzyme with a complementary shape that the substrate binds to
• Enzymes have optimal temperatures and pH levels for maximum activity
• Enzymes can be denatured by extreme temperatures which is permanent or pH levels which is reversible
• The rate of enzyme-catalysed reactions can be measured by the rate of product formation or the rate of substrate disappearance
• Enzyme activity can be affected by factors such as temperature, pH, substrate concentration
• Enzymes are made up of amino acids
• The Benedict's test can be used to detect the presence of reducing sugars
• at optimal temperatures and PH level, there is the highest rate of enzyme substrate collisions = highest rate of enzyme activity
• at low temperatures, there is low KE thus less enzyme substrate collision occur + enzymes are said to be inactive = low enzyme activity
• rising temperatures- enzyme activity increases with temperature until optimum temperature as KE increases , increasing the amount of enzyme substrate collisions
• above optimum temp - denatured enzymes lose their complementary shape of its active site =enzyme substrate complex cannot form = lose its function = decreased enzyme activity
• in the lock and key hypothesis, the enzyme is the lock and the substrate is the key
• PH level enzyme activity graph is more symmetrical while temperature enzyme activity graph is not symmetrical. As increasing / decreasing the PH from optimum will decrease enzyme activity

  
• For PH graph, too much increase / decrease in PH level would cause the enzyme to denatured

  
• Enzymes break up large molecules into smaller molecules so that they can be soluble in water and are small enough to diffuse through the cell membrane