Abstract
A Planck law relationship between absorption and emission spectra is used to compute the fluorescence spectra of some photosynthetic systems from their absorption spectra. Calculated luminescence spectra of purple bacteria agree well but not perfectly with published experimental spectra. Application of the Planck law relation to published activation spectra for Systems I and II of spinach chloroplast permits independent calculation of the luminescence spectra of the two systems; if the luminescence yield of System I is taken to be one-third the yield of System II, then the combined luminescence spectrum closely fits published experimental measurement. Consideration of the entropy associated with the excited state of the absorbing molecules is used to compute the oxidation-reduction potentials and maximum free-energy storage resulting from light absorption. Spinach chloroplasts under an illumination of 1 kilolux of white light can produce at most a potential difference of 1.32 eV for System I, and 1.36 eV for System II. In the absence of non-radiative losses, the maximum amount of free energy stored is 1.19 eV and 1.23 eV per photon absorbed for Systems I and II, respectively. The bacterium Chromatium under an illumination of 1 milliwatt/cm{sup 2} of Na D radiation can produce at most a potential difference of 0.90 eV; the maximum amount of free energy stored is 0.79 eV per photon absorbed. The combined effect of partial thermodynamic reversibility and a finite trapping rate on the amount of luminescence is considered briefly.
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Claims 8
Claim · model-written summary
At 1 kilolux of white light, spinach chloroplasts can produce at most a potential difference of 1.32 eV for System I.
- Taxon
- Spinach
Spinacia oleraceae1 - Organ / stage
- System Ie1
- Treatment
- 1 kilolux of white lighte1
- Outcome
- potential differencee1
- Value
- 1.32 eVe1
- Qualifier
- can produce at moste1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Spinach chloroplasts under an illumination of 1 kilolux of white light can produce at most a potential difference of 1.32 eV for System I, and 1.36 eV for System II”
Claim · model-written summary
At 1 kilolux of white light, spinach chloroplasts can produce at most a potential difference of 1.36 eV for System II.
- Taxon
- SpinachSpinacia oleraceae1
- Organ / stage
- System IIe1
- Treatment
- 1 kilolux of white lighte1
- Outcome
- potential differencee1
- Value
- 1.36 eVe1
- Qualifier
- can produce at moste1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Spinach chloroplasts under an illumination of 1 kilolux of white light can produce at most a potential difference of 1.32 eV for System I, and 1.36 eV for System II”
Claim · model-written summary
In the absence of non-radiative losses, the maximum free energy stored per photon absorbed by spinach System I is 1.19 eV.
- Taxon
- SpinachSpinacia oleraceae1
- Organ / stage
- Systems Ie2
- Outcome
- maximum amount of free energy storede2
- Value
- 1.19 eVe2
- Qualifier
- In the absence of non-radiative lossese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Spinach chloroplasts under an illumination of 1 kilolux of white light can produce at most a potential difference of 1.32 eV for System I, and 1.36 eV for System II”
e2“In the absence of non-radiative losses, the maximum amount of free energy stored is 1.19 eV and 1.23 eV per photon absorbed for Systems I and II, respectively”
Claim · model-written summary
In the absence of non-radiative losses, the maximum free energy stored per photon absorbed by spinach System II is 1.23 eV.
- Taxon
- SpinachSpinacia oleraceae1
- Outcome
- maximum amount of free energy storede2
- Value
- 1.23 eVe2
- Qualifier
- In the absence of non-radiative lossese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Spinach chloroplasts under an illumination of 1 kilolux of white light can produce at most a potential difference of 1.32 eV for System I, and 1.36 eV for System II”
e2“In the absence of non-radiative losses, the maximum amount of free energy stored is 1.19 eV and 1.23 eV per photon absorbed for Systems I and II, respectively”
Claim · model-written summary
The bacterium Chromatium under Na D radiation can produce at most a potential difference of 0.90 eV.
- Taxon
- Chromatium
Chromatiume4 - Treatment
- Na D radiatione3
- Outcome
- potential differencee3
- Value
- 0.90 eVe3
- Qualifier
- can produce at moste3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“of Na D radiation can produce at most a potential difference of 0.90 eV”
e4“The bacterium Chromatium”
Claim · model-written summary
The bacterium Chromatium stores at most 0.79 eV of free energy per photon absorbed.
- Taxon
- ChromatiumChromatiume4
- Outcome
- maximum amount of free energy storede5
- Value
- 0.79 eVe5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“The bacterium Chromatium”
e5“the maximum amount of free energy stored is 0.79 eV per photon absorbed”
Claim · model-written summary
Calculated luminescence spectra of purple bacteria agree well but not perfectly with published experimental spectra.
Verbatim
e6“Calculated luminescence spectra of purple bacteria agree well but not perfectly with published experimental spectra”
Claim · model-written summary
The combined calculated luminescence spectrum closely fits published experimental measurement when System I yield is one-third of System II.
Verbatim
e7“if the luminescence yield of System I is taken to be one-third the yield of System II, then the combined luminescence spectrum closely fits published experimental measurement”