Accessory Pigments

Photosynthetic organisms do not rely on a single pigment to absorb light, but instead benefit from the combined action of many

  • These photosynthetic pigments are grouped into photosystems that absorb and funnel light energy
  • By grouping pigments that have individualised absorption spectra together, the cell maximises its light absorption

When a pigment is energised by light, it releases high energy electrons (

  • Antenna pigments transfer their energised electrons to a central reaction centre
  • From the reaction centre, electrons are passed on to an acceptor molecule in an electron transport chain to synthesise ATP

The presence of accessory pigments explains why not all leaves are green

  • While chlorophyll possesses a green colouration, other pigments (e.g. anthocyanins) may produce different colours
  • Deciduous trees change colour when leaves stop producing chlorophyll in winter when levels of available light are low

Representations of the Transfer of Energy by Antenna Pigments

antenna pigments