Factors affecting enzyme activity

HideShow resource information
View mindmap
  • Factors Affecting Enzyme Activity
    • Temperature
      • Rise provides more kinetic energy to enzyme
      • Too much of a rise causes bonds in enzyme to break
      • Active site will change shape, enzyme and substrate no longer bind
      • Enzyme is denatured
    • pH
      • Optimum pH 7 for most enzymes
      • Pepsin works best at pH 2- found in stomach
      • Above/below optimum pH, H+/OH- ions can affect ionic/hydrogen bonds of tertiary structure
      • Enzyme denatures
    • Enzyme Concentration
      • More enzyme molecules, more collisions, more E-S complexes formed
      • When substrate runs out, adding more enzyme has no further effect
    • Substrate Concentration
      • Higher substrate concentration, more collisions, faster ROR.
      • Reaches 'saturation' point: when all active sites are full, adding substrate has no further effect
      • Decreases with time, so ROR will also decrease. Makes initial ROR highest,
    • Competitive Inhibition
      • Inhibitors have similar shape to substrate
      • Compete to bind to active site
      • Block active site so no other substrates can fit in
      • Can be overcome by adding substrate
    • Non-Competitive Inhibition
      • Bind to enzyme at spot other than active site
      • Causes active site to change shape
      • Substrate can no longer bind
      • Not overcome by increasing substrate concentration
    • End Product Inhibition
      • After reaction has completed, product molecules can stay tightly bound to enzyme
      • Enzyme cannot form more of product than cell needs. Example of neg feedback


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules resources »