Post-Experimental Analysis of the Light-Harvesting Protein–Pigment Complex Present in Green Sulfur Bacteria: An Approach in Quantum Biology

Quantum biology is a multidiscipline which analyses possible critical aspects of life that could be based on the macroscopic expression of quantum phenomena. The high efficiency of light energy harvesting in green sulfur bacteria during photosynthesis is associated with entanglement and tunneling effects in the Fenna–Mathew–Olson complex. This has been studied to assess itscontribution, when conducting the light energy captured by the chlorosome, to the reaction center, where it is transformed into chemical energy. This work analyses, in the quantum domain, the coherence and entanglement between those two components associated with a general non-localized absorption spectrum in the pigments serving as input antennas. This study first imposes a more symmetric structure on the absorption spectrum, revealing certain relations which, when it is partially broken and parametrized on the most feasible pigments, displays a characteristic spectrum associated with the nature of the bacteria studied, in terms of their habitat and evolutionary survival. Finally, a brief insight analysis of similarities and differences in the protein sequence of the complex is conducted to trace possible traits relating them to some of the previous quantum features and suggesting some responsible positions within the FMO protein sequence.