Red Antenna States of Photosystem I from Cyanobacteria <i>Synechocystis</i> PCC 6803 and <i>Thermosynechococcus elongatus</i>: Single-Complex Spectroscopy and Spectral Hole-Burning Study
Bibliographic record
Abstract
Hole-burning and single photosynthetic complex spectroscopy were used to study the excitonic structure and excitation energy-transfer processes of cyanobacterial trimeric Photosystem I (PS I) complexes from Synechocystis PCC 6803 and Thermosynechococcus elongatus at low temperatures. It was shown that individual PS I complexes of Synechocystis PCC 6803 (which have two red antenna states, i.e., C706 and C714) reveal only a broad structureless fluorescence band with a maximum near 720 nm, indicating strong electron-phonon coupling for the lowest energy C714 red state. The absence of zero-phonon lines (ZPLs) belonging to the C706 red state in the emission spectra of individual PS I complexes from Synechocystis PCC 6803 suggests that the C706 and C714 red antenna states of Synechocystis PCC 6803 are connected by efficient energy transfer with a characteristic transfer time of approximately 5 ps. This finding is in agreement with spectral hole-burning data obtained for bulk samples of Synechocystis PCC 6803. The importance of comparing the results of ensemble (spectral hole burning) and single-complex measurements was demonstrated. The presence of narrow ZPLs near 710 nm in addition to the broad fluorescence band at approximately 730 nm in Thermosynechococcus elongatus (Jelezko et al. J. Phys. Chem. B 2000, 104, 8093-8096) has been confirmed. We also demonstrate that high-quality samples obtained by dissolving crystals of PS I of Thermosynechococcus elongatus exhibit stronger absorption in the red antenna region than any samples studied so far by us and other groups.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".