Biological complexity: photosynthesis molecular controls (Introduction)

by David Turell , Monday, July 06, 2020, 18:33 (1601 days ago) @ David Turell

A new description of an active molecule in the process:

https://phys.org/news/2020-07-quench-role-cyanobacterial-photosystem-protein.html

"...the details of photosynthesis—the key process that supports all forms of advanced lives on earth—have been studied for many decades. And all studies, despite their differences, reveal one thing: that it is an astonishingly precise process, consisting of numerous small reactions run by many proteins and their combinations. However, the molecular-level details of many of these steps are still not understood very well.

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"In the cyanobacterial membrane, IsiA appears in low iron level conditions, and combines with a trimeric core of PSI to perform the light-harvesting step. Much akin to a runner in a relay race, IsiA "donates" or transfers the captured energy to the trimeric core of PSI that performs the subsequent step in the photosynthesis process. It has been believed that in addition to functioning an "energy harvester," IsiA also works as a "quencher" that gets rid of excess energy as heat when light intensity is too high for the cells to grow.

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"The result of this study ruled out the possibility of any energy-quenching taking place in the IsiA-PSI core supercomplex, confirming IsiA's role as an energy harvester and donor.
Highlighting the significance of this exciting study, Dr. Akita states, "These structural and spectroscopic findings provide important insights into the molecular arrangement and energy-transfer mechanisms in the photosystems of cyanobacteria. A deeper understanding of how photosynthetic energy transfer takes place will help to develop new energy devices based on photosynthesis.'"

Comment: Be sure to see the diagram of the molecule. Obviously a designed process.