Scientists at the University of Vienna have observed an interference pattern for molecules of tetraphenylporphyrin, the key component of light-absorbing chlorophyll in plants and oxygen-binding haemoglobin in blood.

This quantum behavior was thought to be limited to subatomic particles and individual atoms. The finding raises questions about larger biological molecules and may have implications for the Penrose-Hameroff proposal that consciousness might arise from wave-like quantum-mechanical effects involving protein filaments called microtubules in nerve cells.

Also see “Biomolecule behaves like a wave,” Physics Web, September 2003.