Excitation transfer rates in a cyanobacterial photosystem I in the dipolar coupling approximation

Authors

  • Ron Michael V. Acda ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Francis N. C. Paraan ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

Photosystems are light-harvesting units utilized by photosynthetic organisms. The arrangement of chlorophylls (Chl) in each photosystem varies from organism to organism and is fine-tuned by evolution. In this paper, we study the pathways of excitation transfer in a cyanobacterial photosystem I (Synechococcus elongatus) using an effective Hamiltonian based on Förster theory of resonance energy transfer. The off-diagonal terms of the Hamiltonian matrix were calculated in the dipolar coupling approximation to obtain excitation transfer rates between Chl pairs in the network. From these rates, it was found that there is a four-fold preferential excitation flow from the peripheral antenna to the B39 Chl compared to A40. The transfer rate discrepancy can be attributed to the difference in the dipole moment orientations and the spatial locations of the central Mg atom of the Chls. Strongly coupled antenna Chls were identified based on a threshold on the maximum transfer rates.

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Issue

Article ID

SPP-2023-PB-15

Section

Poster Session B (Complex Systems, Simulations, and Theoretical Physics)

Published

2023-07-09

How to Cite

[1]
RMV Acda and FNC Paraan, Excitation transfer rates in a cyanobacterial photosystem I in the dipolar coupling approximation, Proceedings of the Samahang Pisika ng Pilipinas 41, SPP-2023-PB-15 (2023). URL: https://proceedings.spp-online.org/article/view/SPP-2023-PB-15.