Biological complexity: how photosynthesis controls electrons (Introduction)

by David Turell , Thursday, February 06, 2020, 00:14 (1753 days ago) @ David Turell

More new research:

https://www.sciencedaily.com/releases/2020/02/200205132347.htm

"Scientists recently solved a critical part of this age-old mystery, homing in on the initial, ultrafast events through which photosynthetic proteins capture light and use it to initiate a series of electron transfer reactions.

"'In order to understand how biology fuels all of its engrained activities, you must understand electron transfer," said Argonne biophysicist Philip Laible. "The movement of electrons is crucial: it's how work is accomplished inside a cell."

"In photosynthetic organisms, these processes begin with the absorption of a photon of light by pigments localized in proteins.

"Each photon propels an electron across a membrane located inside specialized compartments within the cell.

"'The separation of charge across a membrane -- and stabilization of it -- is critical as it generates energy that fuels cell growth," said Argonne biochemist Deborah Hanson.

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"The scientists' recent article, "Switching sides -- Reengineered primary charge separation in the bacterial photosynthetic reaction center," published in the Proceedings of the National Academy of Sciences, shows how they discovered an engineered version of this protein complex that switched the utilization of the pathways, enabling the one that was inactive while disabling the other.

"'It is remarkable that we have managed to switch the direction of initial electron transfer," said Christine Kirmaier, Washington University chemist and project leader. "In nature, the electron chose one path 100 percent of the time. But through our efforts, we have been able to make the electron switch to an alternate path 90 percent of the time. These discoveries pose exciting questions for future research.'"

Comment: The electron transfer is critical and very complex. Design required.