Discovery of phase transitions in photosynthetic systems

Abstract The temperature dependence of Stokes Raman scattering from green monocellular algae ( Chlorella pyrenoidosa ) indicates that phase transitions which involve the photoactive pigment molecules occur during warming up at 230 K and 261 K. It is shown that these collective structural rearrangements lead to a spectral shape which is known from Raman experiments with living cells.