Cofactors, coenzymes and prosthetic groups

Cofactors and coenzymes

  • both non protein ‘helper’ components that are needed for enzymes to be able to carry out their function as a biological catalyst

    • the cofactor or co enzyme might transfer atoms or groups from one reaction to another in a multi step pathway

    • or may form part of the active site of the enzyme

  • cofactors and coenzymes

Cofactors vs coenzymes

  • cofactors

    • INORGANIC

    • often obtained as minerals from diet eg. iron, calcium, chloride and zinc ions

    • eg. amylase needs a chloride ion to form right shaped active site

    • cofactor

  • coenzyme

    • ORGANIC

    • often derived from vitamins in our diet

    • eg. vitamin B3 is used to synthesise the coenzyme NAD which transfers hydrogen atoms between molecules during the respiration pathway

    • coenzyme

Prosthetic groups

  • bind permanently to enzyme via covalent bonding

  • form part of the enzyme structure

  • can be organic or inorganic