This process, a critical component of photosynthesis, is the most efficient energy-transfer process known, yet in many ways it is still poorly understood.One of the most mysterious aspects of photosynthesis is the mechanism behind its efficiency.
We want to know this because photosynthesis is fundamental to all forms of life on Earth but also, if you can understand how photosynthesis works, some time in the future you might be able to use that knowledge to more efficiently capture energy from the sun.” In 2007 the world’s two leading scientific journals – Science and Nature – published research that suggested a phenomenon known as quantum coupling was a major contributor to the efficiency of energy transfer in photosynthesis.
Professor Hannaford, director of Swinburne’s Centre for Atom Optics and Ultrafast Spectroscopy, explains that at the subatomic level, the level at which photosynthesis occurs, an electron can be in two internal quantum states.
The laws of quantum mechanics allow the electron to be in a superposition of the two states, such that it is in multiple locations simultaneously.
When this occurs across different molecules, they are said to be quantum coupled.
“We know roughly where the energy is absorbed and where it goes to, but we don’t know the precise mechanisms.
“We want to know what’s happening in the light-harvesting complex.Photosynthesis converts light energy from the sun into chemical energy stored in organic compounds, which are used to build the cells of producers and ultimately fuel ecosystems.After providing an overview of photosynthesis, these animations zoom inside the cells of a leaf and into a chloroplast to see where and how the reactions of photosynthesis happen.It is this mechanism that Professor Peter Hannaford and Dr Jeff Davis from Swinburne University of Technology are rying to expose.They are particularly interested in a pigment called lycopene, which gives tomatoes their red colour but which is also an important molecule in photosynthesis.“We’re seeing long-lived quantum coupling between energy states in lycopene, which makes it possible that you then get efficient energy transfer to the rest of the light-harvesting complex,” he says.As more experimental data is gathered it will be sent to Professor Yasushi Koyama from Kwansei Gakuin University in Japan, an expert in carotenoids (plant pigments that capture sunlight for photosynthesis).Depending on students’ background, it may be helpful to pause the animations at various points to discuss different steps or structures.The accompanying “Student Worksheet” incorporates concepts and information from the animations.The animations detail both the light reactions and the Calvin cycle, focusing on the flow of energy and the cycling of matter.This animation series contains seven parts, which can be watched individually or in sequence.