Cofactors, coenzymes and prosthetic groups

• Cofactors:

  • Non-protein helper helping enzymes
  • Can transfer atoms or groups from one reaction to another in a multi-step pathway
  • May form part of the active site
• Coenzyme - An organic cofactor
• Inorganic cofactors:

  • Obtained via diet - Minerals containing ions
• Coenzymes - Obtained by vitamins
• Prosthetic groups - Are cofactors that are tightly bound and a permenant feature of the enzyme
• E.g. of cofactor - Chloride ion:

  • Within amylase - Catalyses the breakdown of starch
  • Necessary for the formation of a correctly shaped active site
• e.g. Prosthetic group - Zinc ions:

  • Within carbonic anhydrase
  • Necessary for metabolism of carbon dioxide
• Inactive precursor enzymes - Different types:

  • Enzymes that are produced in inactive form
  • Particularly can cause damage within cells or tissues
  • Actions need to be controlled and only activated under certain conditions
• Adding cofactor to Precursor enzymes - Tertiary structure for active site changed