Incorporation of Inorganic Phosphate into Sugar Phosphates during Carbon Dioxide Fixation by Illuminated Chloroplasts

Nature ◽  
1966 ◽  
Vol 210 (5038) ◽  
pp. 793-796 ◽  
Author(s):  
C. W. BALDRY ◽  
C. BUCKE ◽  
D. A. WALKER
Keyword(s):  
Carbon Dioxide ◽  
Inorganic Phosphate ◽  
Carbon Dioxide Fixation ◽  
Sugar Phosphates

Stomatal Metabolism: Carbon Dioxide Fixation in Attached and Detached Epidermis of Commelina

1978 ◽  
Vol 5 (6) ◽  
pp. 767
Author(s):  
C.M Wilmer ◽  
N Thorpe ◽  
J.C Rutter ◽  
F.L Milthorpe
Keyword(s):  
Carbon Dioxide ◽  
Tca Cycle ◽  
Carbon Dioxide Fixation ◽  
Reverse Direction ◽  
Gaseous Exchange ◽  
14Co2 Fixation ◽  
Fixation Pattern ◽  
The Difference ◽  
Sugar Phosphates ◽  
Tca Cycle Intermediates

Rates of accumulation of radioactivity and the nature of 14CO2 fixation products were measured in mesophyll, attached epidermis and detached epidermis of Commelina cyanea and C. communis. In the illuminated detached epidermis of C. cyanea, most of the fixation products were malate and aspartate (in almost equal proportions), with small amounts of sugars, sugar phosphates, serine, glycine, alanine and TCA cycle intermediates. In that of C. communis there was a smaller proportion of aspartate and a higher proportion of sugars, glutamate and tricarboxylic acids. The much higher rates of accumulation of labelled fixation products in attached epidermis of C. cyanea can in part be attributed to glycine, serine and alanine, which appear to be imported from the mesophyll very shortly after the leaf is first exposed to 14CO2. Over longer periods of time, labelled sugars contributed an appreciable and increasing proportion. In C. communis, after 15-30 min, most of the difference between attached and detached epidermis was attributable to the presence of labelled sugars. The fixation pattern in the mesophyll of these species was typical of C*3-type photosynthesis. Autoradiographs of detached epidermis showed that the label was predominantly in stomata while those of attached epidermis showed more label in stomata than elsewhere after 1 min and they were uniformly labelled after 30 min. These findings suggest that metabolites are translocated from the mesophyll to the epidermis fairly readily. There is probably flow in the reverse direction as well as gaseous exchange of 14C between these tissues.

scholarly journals Some effects of sugars and sugar phosphates on carbon dioxide fixation by isolated chloroplasts

1966 ◽  
Vol 101 (3) ◽  
pp. 636-641 ◽  
Author(s):  
C Bucke ◽  
DA Walker ◽  
CW Baldry
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Fixation ◽  
Free Sugars ◽  
Sugar Phosphates ◽  
Related Compounds ◽  
Isolated Chloroplasts

1. Carbon dioxide fixation by isolated pea chloroplasts was stimulated by the addition of intermediates of the Calvin photosynthesis cycle and by some related compounds. 2. Ribose 5-phosphate and fructose 1,6-diphosphate consistently produced the largest effects; free sugars such as erythrose and sedoheptulose and acids such as glycollate and glyoxylate were largely ineffective or even inhibitory. 3. Small effects were produced by fructose and ribose but not by their isomers, glucose and xylose. 4. Maximal rates in the presence of ribose 5-phosphate varied between 10 and 50mumoles of carbon dioxide fixed/mg. of chlorophyll/hr.

scholarly journals Calvin-cycle intermediates in relation to induction phenomena in photosynthetic carbon dioxide fixation by isolated chloroplasts

1966 ◽  
Vol 101 (3) ◽  
pp. 642-646 ◽  
Author(s):  
CW Baldry ◽  
DA Walker ◽  
C Bucke
Keyword(s):  
Carbon Dioxide ◽  
Calvin Cycle ◽  
Carbon Dioxide Fixation ◽  
Chloroplast Envelope ◽  
Induction Periods ◽  
New Synthesis ◽  
Photosynthetic Carbon ◽  
Sugar Phosphates ◽  
Isolated Chloroplasts ◽  
Additional Fixation

1. Induction periods in carbon dioxide fixation by isolated pea chloroplasts were shortened by small quantities of Calvin-cycle intermediates. The additional fixation was larger than that which would have followed direct stoicheiometric conversion into ribulose 1,5-diphosphate. 2. When chloroplasts were illuminated in the absence of added substrates (other than carbon dioxide) soluble products were formed in the medium that stimulated fixation by fresh chloroplasts. 3. The induction periods were lengthened by washing the chloroplasts. Addition of catalytic quantities of Calvin-cycle intermediates then decreased the induction periods to their previous values. 4. The induction period was extended by a decrease in temperature but was largely unaffected by a decrease in light-intensity that was sufficient to decrease the maximum rate. 5. It is concluded that the lag periods are a consequence of the loss of Calvin-cycle intermediates, such as sugar phosphates, through the intact chloroplast envelope and that these losses can be made good by new synthesis from carbon dioxide in the reactions of the Calvin cycle.

Stomatal Metabolism: Carbon Dioxide Fixation and Labelling Patterns during Stomatal Movement in Commelina cyanea

1979 ◽  
Vol 6 (3) ◽  
pp. 409
Author(s):  
N Thorpe ◽  
C.M Willmer ◽  
F.L Milthorpe
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Fixation ◽  
Stomatal Movement ◽  
Sugar Phosphates

Epidermal strips floated on solutions with NaH14CO3 fixed 14C about three times as quickly when the stomata were opening or closing as they did when either open or closed. The proportions of the major fixation products-malate, aspartate, sugars and sugar phosphates, glycine, serine and alanine-were very similar during the opening, open and closed phases but, when closing, an appreciably higher proportion was diverted to sugars and sugar phosphates. There was a relatively greater leakage into the medium of labelled malate during the open, closed and closing phases than during opening.

scholarly journals CARBON DIOXIDE FIXATION IN ISOCITRIC ACID

1947 ◽  
Vol 170 (2) ◽  
pp. 461-465
Author(s):  
Santiago Grisolia ◽  
Birgit Vennesland
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Fixation ◽  
Isocitric Acid

scholarly journals THE PREPARATION OF C14-LABELED BIOTIN AND A STUDY OF ITS STABILITY DURING CARBON DIOXIDE FIXATION

1949 ◽  
Vol 180 (1) ◽  
pp. 299-305 ◽  
Author(s):  
Donald B. Melville ◽  
John G. Pierce ◽  
C.W.H. Partridge
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Fixation

scholarly journals BIOSYNTHESIS OF TRICARBOXYLIC ACIDS BY CARBON DIOXIDE FIXATION

1948 ◽  
Vol 174 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Severo Ochoa ◽  
Erna Weisz-Tabori
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Fixation
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