This project focuses on two fundamental quantum biological phenomena in nature that are related by similar physical mechanisms involving interaction of light with living systems. The first phenomenon to be examined is animal magnetoreception, the process by which certain animals employ a magnetic compass for navigation. A specific protein, cryptochrome, is proposed to be responsible for the magnetic sense. This project will determine how cryptochrome can function as a magnetic sensor in the presence of thermal motion. The second phenomenon to be studied is photosynthetic light harvesting, the primary process by which the energy of sunlight is funneled into the life processes of living cells. Again the effect of thermal disorder on light harvesting will be investigated along with the role that quantum coherence plays. Extensive stochastic quantum dynamics calculations will be carried out to account for realistic system-environment interactions during light harvesting. The composition and organization of a complete photosynthetic apparatus, the chromatophore, of so-called purple bacteria, will be determined along with the dynamics of its light-harvesting function, thereby connecting the photosynthetic process across scales from individual pigments to entire cells.
The project will have two primary beneficial impacts. First, solar energy, received on Earth at a rate of 120,000 TW, far exceeds the current worldwide energy consumption rate of 15 TW. Therefore, solar energy, harvested by biological, artificial, and bio-hybrid systems, constitutes a potential renewable source for mankind's current and foreseeable future energy needs. The project will guide efforts into biomimetic light harvesting materials for more cost-effective solar technology. Second, damage by birds and other wildlife striking aircraft, annually amounts to well over $600 million for US civil and military aviation; over 219 people have been killed worldwide as a result of wildlife strikes since 1988. Determining the mechanisms of animal navigation may reduce the property damage as well as harm to wildlife. Additionally, this project offers a basis for interdisciplinary cooperation between experimental biologists, theoretical physicists, theoretical chemists, and computer scientists, providing an excellent training opportunity for researchers. Lastly, planned activities will complement an existing strong outreach program for bringing science to the public at large. Advanced visualization and analysis tools will be added to the freely available leading molecular visualization and analysis tools developed by the PI and will be made available to an existing base of 167,000 users. This project is jointly supported by the Biomolecular Dynamics, Structure and Function Cluster in the Division of Molecular and Cellular Biosciences and the Physics of Living Systems Program in the Physics Division.
