Abstract
Factors affecting CO(2) fixation in the spinach (Spinacia oleracea) chloroplast were investigated. Free magnesium ions are shown to be highly inhibitory for photosynthetic CO(2) fixation in isolated intact spinach chloroplasts. The pH optimum for CO(2) fixation is about 8.5 but is dependent upon the reaction medium. Conditions are defined under which chloroplasts illuminated in the absence of CO(2) accumulate ribulose 1,5-diphosphate, and fix CO(2) in a subsequent dark period when high magnesium ion concentrations are provided. The regulation of photosynthetic CO(2) assimilation by these factors is discussed.
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Claims 4
Claim · model-written summary
Free magnesium ions strongly inhibited photosynthetic carbon dioxide fixation in isolated intact spinach chloroplasts.
- Taxon
- spinach
Spinacia oleraceae0 - Organ / stage
- chloroplastse0
- Treatment
- Free magnesium ionse0
- Outcome
- photosynthetic CO(2) fixatione0
- Direction
- highly inhibitorye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Free magnesium ions are shown to be highly inhibitory for photosynthetic CO(2) fixation in isolated intact spinach chloroplasts.”
Claim · model-written summary
The pH optimum for spinach chloroplast carbon dioxide fixation was about 8.5 and depended on reaction medium.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- pH optimum for CO(2) fixatione0
- Value
- 8.5e0
- Qualifier
- dependent upon the reaction mediume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The pH optimum for CO(2) fixation is about 8.5 but is dependent upon the reaction medium.”
t0“Spinach”
Claim · model-written summary
Illuminated chloroplasts without carbon dioxide accumulated ribulose 1,5-diphosphate under defined conditions.
- Taxon
- spinachSpinacia oleraceat0
- Organ / stage
- chloroplastse0
- Treatment
- illuminated in the absence of CO(2)e0
- Outcome
- accumulate ribulose 1,5-diphosphatee0
- Direction
- accumulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chloroplasts illuminated in the absence of CO(2) accumulate ribulose 1,5-diphosphate”
t0“Spinach”
Claim · model-written summary
Under those conditions, spinach chloroplasts fixed carbon dioxide in a subsequent dark period with high magnesium ion concentrations.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- fix CO(2)e0
- Qualifier
- in a subsequent dark period when high magnesium ion concentrations are providede0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fix CO(2) in a subsequent dark period when high magnesium ion concentrations are provided.”
t0“Spinach”
The same questions in other papers
magnesium ion · physiology: photosynthesis · Spinacia oleracea (spinach)Results agree
1 paper in the same direction as this paper
- negative
co2 · molecular: metabolites · Spinacia oleracea (spinach)Positive and negative results
2 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- no effect
- negative
2 papers more in this group
See all 6 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.