Chlorophyll Molecules and Green Bacteria (IMAGE) Penn State Caption The Nuclear Magnetic Resonance (NMR) results enabled the scientists to determine that the chlorophyll molecules (shown in green and orange) in green bacteria are arranged in helical spirals, and are positioned at an angle to the long axis of the nanotubes. Credit Image by Donald Bryant, Penn State University, courtesy of Proceedings of the National Academy of Sciences Usage Restrictions The credit line -- Image by Donald Bryant, Penn State University, courtesy of Proceedings of the National Academy of Sciences-- must be published along with the picture. 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.