Scientists Use Light to Control Proteins (IMAGE) Penn State Caption The scientists attached a light-sensing protein (sensor) from the oat plant to an enzyme from E. coli. When they shined white light (stimulus) on the sensor, the enzyme's acitvity increased (output). Credit Benkovic lab, Penn State Usage Restrictions The credit information must be published along with the image. 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.