2, Chemistry, Texas A&M University, College Station, Texas, United States
Quantum phenomena are intrinsic to many living systems. A number of these phenomena will be explained conceptually including the biggest quantum machine in humans: the brain. The talk will allude to (i) brain hemispheres and their synchronization, (ii) entangled brain waves and related health benefits, (iii) the differentiation between the conscious and unconscious mind and its impact on self-transformation and well-being, (iv) the synchronous and asynchronous firing of neurons and how this relates to everyday problems as well as (v) pre-sentiment responses across the scales. Another fine example is the highly efficient quantum coherence-enabled energy-transfer processes employed by photosynthetic organisms. With regards to the latter, checking the truth of the underlying principles is challenging as the experimental measurements employed may perturb a quantum system into a classical one. This has been a concern with 2DES experiments employing ultrashort broadband laser pulses when probing the quantum processes of photosynthesis. Here we uncover the foundations of photosynthetic energy transfer as a role model for other biological quantum systems using an approach that extends experimental data into those realms where the use of a non-perturbing approach is critically required. To this end, this project uses quantum chemical calculations to three-dimensionally map the patterns of quantum and non-quantum effects observed in the highly effective energy transfer process of photosynthesis. Combining X-ray and electron tomographic data into an atomistic model as a starting point, we project to unravel the energy transfer patterns within the confinement of a single PSII component (intra-subunit) and then across the subunit boundaries (inter-subunit) to cover the entire complex. Intra-subunit: Investigations thus far have focused on UV-Vis spectra calculations to investigate the level of communication between chlorophyll chromophores in the LHCII subunit and the well-known strongly coupled special Chla/Chla pair (P680) in the D1/D2 subunit. Inter-subunit: This work will start with a refined all atom model fitted to an in situ tomographic data set. Based on the intra-subunit energy pathway peripheral chromophores delineating individual subunit-subunit contacts will be FRET-correlated to elucidate the most likely energy bridges between the two subunits in question. Eventually the full dielectric patterns of the energy transfer pathway between all PSII core and antennae components will be determined inching through the entire complex from one chromophore couple to the next.
Basing the analysis of energy transfer on a biological macromolecular complex, means any conclusions drawn are a priori based on a system derived from earth-abundant elements thus making this approach particularly attractive for next generation technologies such as quantum computing, organic photovoltaics or artificial intelligence.