Photosynthesis research leans on a handful of characteristic measurements, each capturing a different slice of the light reactions or carbon fixation. Below is what the raw data typically looks like for each technique, and which of the curated models can reproduce and explain it. Jump straight to the matching models from any section.
Pulse-amplitude-modulation fluorometry tracks chlorophyll a fluorescence while firing saturating pulses. The decline of the peak (Fm → Fm′) reports non-photochemical quenching (NPQ); the steady level gives PSII operating efficiency. Classic readouts are induction/relaxation kinetics and rapid light curves.
A dark-adapted leaf hit with strong light shows a polyphasic fluorescence rise through the O, J, I and P steps over microseconds to a second. The shape probes the state and connectivity of PSII and the electron-acceptor pool size — a fast, sensitive stress phenotype.
Infrared gas analysis measures net CO₂ uptake against light (A/Q) or intercellular CO₂ (A/Ci). The saturating response separates Rubisco-, electron-transport- and TPU-limited regimes — the domain of Farquhar–von Caemmerer–Berry steady-state models.
Absorbance changes near 820–870 nm follow the redox state of the PSI reaction-centre donor P700. Under a saturating pulse P700 is oxidised and re-reduces in the dark, reporting PSI photochemistry, donor-side limitation and cyclic electron flow.
The ~515 nm electrochromic band shift is linear in the trans-thylakoid electric field. Its light-on rise and dark-interval relaxation (DIRK) quantify the proton-motive force and its partitioning into ΔΨ and ΔpH.