Radiation-entropy generation by leaf and negentropy build-up of plant as dissipative structure

Abstract

Photosynthesis is a simple reaction for any plant, but it has not been achieved artificially due to the difficulty in radiation entropy production by processing PAR (photosynthetically active radiation). In this study, a plant is shown to be a self-organising dissipative structure; since, it’s leaf generates radiation entropy for the existence of plant with possible growth. Entropy-energy ratio (s_E) of PAR released after processing (s_E,rel) much exceeds s_E of light absorbed, s_E,in (< < s_E,rel). Plant builds its negentropy \(\left| {s_{{{\text{neg}},{\text{rad}}}} } \right|\) by the difference, \(s_{{\text{E,rel}}} - s_{{\text{E,in}}}\) , but only a part of this difference can be the source of free energy as plant-growth. The remaining part of \(\left| {s_{{{\text{neg}},{\text{rad}}}} } \right|\) is dissipated as the excess payment of negentropy debt, towards mandatory 2nd Law compliance. Change from low s_E,in to high s_E,rel by the plant-leaf is amplified by a huge factor, c², while determining \(\left| {s_{{{\text{neg}},{\text{rad}}}} } \right|\); where, c is the speed of light. Therefore, even a small increase in s_E,rel and small reduction in s_E,in can significantly increase \(\left| {s_{{{\text{neg}},{\text{rad}}}} } \right|\). Thermodynamic performance of photosynthesis depends on the processing level of PAR, \(\Pi_{{{\text{E}},{\text{leaf}}}} = \left( {{{s_{{{\text{E}},{\text{rel}}}} } \mathord{\left/ {\vphantom {{s_{{{\text{E}},{\text{rel}}}} } {s_{{{\text{E}},{\text{in}}}} }}} \right. \kern-0pt} {s_{{{\text{E}},{\text{in}}}} }}} \right)\), \(\left| {s_{{{\text{neg}},{\text{rad}}}} } \right|\), and is limited by the maximum photosynthetic efficiency in PAR, \({\upeta }_{{{\text{ph}},{\text{PAR}}\_{\text{max}}}}\) (it increases with \(\Pi_{{{\text{E}},{\text{leaf}}}}\)).

Graphical Abstract