Investigating Photosystem II (IMAGE) California Institute of Technology Caption This illustration depicts a metal cluster prepared by the Agapie group at Caltech on a background of photosystem II, the protein complex that performs photosynthesis in leaves. Credit Emily Tsui/Caltech Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.