The induction of inorganic carbon transport and external carbonic anhydrase in <i>Chlamydomonas reinhardtii</i> is regulated by external CO<sub>2</sub> concentration
Bibliographic record
Abstract
ABSTRACT Induction of the carbon concentrating mechanism (CCM) has been investigated during the acclimation of 5% CO 2 ‐grown Chlamydomonas reinhardtii 2137 mt + cells to well‐defined dissolved inorganic carbon ( C i ) limited conditions. The CCM components investigated were active HCO 3 − transport, active CO 2 transport and extracellular carbonic anhydrase (CA ext ) activity. The CA ext activity increased 10‐fold within 6 h of acclimation to 0·035% CO 2 and there was a further slight increase over the next 18 h. The CA ext activity also increased substantially after an 8 h lag period during acclimation to air in darkness. Active CO 2 and HCO 3 − uptake by C. reinhardtii cells were induced within 2 h of acclimation to air, but active CO 2 transport was induced prior to active HCO 3 − transport. Similar results were obtained during acclimation to air in darkness. The critical C i concentrations effecting the induction of active C i transport and CA ext activity were determined by allowing cells to acclimate to various inflow CO 2 concentrations in the range 0·035–0·84% at constant pH. The total C i concentration eliciting the induction and repression of active C i transport was higher during acclimation at pH 7·5 than at pH 5·5, but the external CO 2 concentration was the same at both pHs of acclimation. The concentration of external CO 2 required for the full induction and repression of C i transport and CA ext activity were 10 and 100 μ M , respectively. The induction of CA ext and active C i transport are not correlated temporally, but are regulated by the same critical CO 2 concentration in the medium.
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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".