EVOLUTION OF CARBON DIOXIDE BY TOBACCO LEAVES DURING THE DARK PERIOD FOLLOWING ILLUMINATION WITH LIGHT OF DIFFERENT INTENSITIES

1961 ◽  
Vol 39 (5) ◽  
pp. 1045-1056 ◽  
Author(s):  
E. B. Tregunna ◽  
G. Krotkov ◽  
C. D. Nelson
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Short Duration ◽  
Dark Period ◽  
Light Period ◽  
Closed Circuit ◽  
Carbon Dioxide Evolution ◽  
Tobacco Leaves

Detached tobacco leaves were placed in a closed-circuit apparatus and the air was continuously circulated over the leaves and through an infrared CO2 analyzer. From the known volume of the apparatus and the percentage of carbon dioxide in its air, the amounts of carbon dioxide either absorbed or evolved by a leaf were calculated.When, after a period of illumination, leaves were darkened, the attainment of their steady rates of respiration was preceded by two outbursts of carbon dioxide evolution. Since these outbursts occurred only after a period of illumination, it has been concluded that both were the result of photostimulation. The peak of the first outburst was usually considerably higher than that of the second. It was of short duration and the height of its peak was accentuated by the increased light intensity in the preceding light period. The second outburst lasted longer and prior light intensity had no effect on the height of its peak.

FURTHER EVIDENCE ON THE EFFECTS OF LIGHT ON RESPIRATION DURING PHOTOSYNTHESIS

1964 ◽  
Vol 42 (8) ◽  
pp. 989-997 ◽  
Author(s):  
E. B. Tregunna ◽  
G. Krotkov ◽  
C. D. Nelson
Keyword(s):  
Carbon Dioxide ◽  
Initial Rate ◽  
Dark Period ◽  
Photosynthetic Apparatus ◽  
Carbon Dioxide Production ◽  
Carbon Dioxide Evolution ◽  
Tobacco Leaves ◽  
Close Relationship

Chlorophyll-rich and chlorophyll-deficient leaves of soybean, peperomia, and corn were compared for the effects of previous illumination on the rate of carbon dioxide evolution in the subsequent dark period. An infrared carbon dioxide analyzer was used to measure these rates. It was found that the initial rate of carbon dioxide production in the dark was affected by previous illumination in proportion to the capacity of the leaves for photosynthesis. Light accelerated carbon dioxide production in green soybean and perperomia leaves, but inhibited it in green corn leaves.Using a Geiger tube to follow changes in the concentration of C14O2 around detached tobacco leaves, it was concluded that some recent product of photosynthesis was the substrate for the initial postillumination production of carbon dioxide. All above results indicated that there was a close relationship between the photosynthetic apparatus of the leaves and the production of carbon dioxide both during and immediately following a period of illumination.

Diel Periodicity of Chlorophyll a Concentration in Oregon Coastal Waters

1972 ◽  
Vol 29 (9) ◽  
pp. 1253-1259 ◽  
Author(s):  
Walter A. Glooschenko ◽  
Herbert Curl Jr. ◽  
Lawrence F. Small
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Dark Period ◽  
Skeletonema Costatum ◽  
Time Of Day ◽  
Light Period ◽  
Diel Periodicity ◽  
Low Light ◽  
Chlorophyll Precursor

Concentrations of chlorophyll a in phytoplankton exhibited a diel periodicity in Oregon coastal waters. Maximum surface concentrations often occurred around midnight and highest 25-m concentrations early in the evening (or even in late afternoon). Concentrations at intermediate depths fell in between and in a predictable progression with depth and time of day. Minimum chlorophyll a values occurred in the afternoon. No definite periodicity was established at 50 m.Laboratory studies with Skeletonema costatum demonstrated that the diel cycle of chlorophyll a per cell was related to the light intensity and duration to which cells were exposed. Highest concentrations of this pigment occurred early in the dark period and lowest concentrations in the light period when cells were grown under photoperiods of 9, 12, and 15 hr at a light intensity of approximately 1200 ft-c. Pigment bleaching probably was responsible for the low concentrations during the light period. The decline of chlorophyll a from the maximum early in the dark period began after the cells possibly became deficient in some chlorophyll precursor or energy-yielding substrate. Addition of an external carbon source during the dark period prolonged the high chlorophyll a concentrations in the dark before the decline began. Under low light (400 ft-c) chlorophyll a synthesis occurred only in the light. This phenomenon was most likely due to an insufficient amount of energy-yielding substrate or precursor synthesized during the low-light period, and the lack of bleaching in the light period at this lower intensity. The laboratory results were consistent with interpretations of the field data. A correction for diel pigment periodicity is recommended for models estimating photosynthesis from chlorophyll and light data and for oceanographic surveys during which sampling of chlorophyll a is carried out throughout the 24-hr day.

Chemical Properties of Tobacco Leaves as Affected by Carbon Dioxide Depletion and Light Intensity 1

1973 ◽  
Vol 65 (6) ◽  
pp. 988-992 ◽  
Author(s):  
C. David Raper ◽  
W. W. Weeks ◽  
R. J. Downs ◽  
W. H. Johnson
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Chemical Properties ◽  
Tobacco Leaves

scholarly journals PHOTOXIDATION PROCESSES IN PLANTS

1941 ◽  
Vol 25 (2) ◽  
pp. 309-324 ◽  
Author(s):  
J. Franck ◽  
C. S. French
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Oxygen Pressure ◽  
Dark Period ◽  
Saturation Curve ◽  
Similar Dependence ◽  
Rate Of Photosynthesis ◽  
Kinetics Of ◽  
Saturation Rate

1. Photoxidation in leaves is measured by exposing them to light in an atmosphere free from carbon dioxide but containing varied percentages of oxygen. 2. Photoxidation is observed in living leaves as well as in dead ones and in plant juices. Its rate is only slightly enhanced by feeding the leaves with sugar, but the respiration (autoxidation) becomes considerably enlarged during the exposure and the following dark period. 3. The rate of photoxidation rises slower than linearly with light intensity; its dependence upon oxygen pressure has the character of a saturation curve. Oxygen saturation occurs at about 6/10 of an atmosphere of oxygen. A similar dependence on oxygen pressure has been observed by Gaffron for photoxidation in vitro sensitized by chlorophyll adsorbed on proteins and by Warburg for the depression of the saturation rate of photosynthesis. 4. The influence of photoxidation on photosynthesis and the chemical kinetics of photoxidation are discussed.

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

scholarly journals Investigation and Possibilities of Reuse of Carbon Dioxide Absorbent Used in Anesthesiology

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5052
Author(s):  
Bartłomiej Rogalewicz ◽  
Agnieszka Czylkowska ◽  
Piotr Anielak ◽  
Paweł Samulkiewicz
Keyword(s):  
Carbon Dioxide ◽  
Thermal Properties ◽  
Powder Diffraction ◽  
Soda Lime ◽  
Closed Circuit ◽  
Carbon Dioxide Absorption ◽  
X Ray ◽  
Kinetics Of ◽  
Carbon Dioxide Absorbent

Absorbents used in closed and semi-closed circuit environments play a key role in preventing carbon dioxide poisoning. Here we present an analysis of one of the most common carbon dioxide absorbents—soda lime. In the first step, we analyzed the composition of fresh and used samples. For this purpose, volumetric and photometric analyses were introduced. Thermal properties and decomposition patterns were also studied using thermogravimetric and X-ray powder diffraction (PXRD) analyses. We also investigated the kinetics of carbon dioxide absorption under conditions imitating a closed-circuit environment.

SEXUAL BEHAVIOUR OF THE MEDITERRANEAN FLOUR MOTH, ANAGASTA KÜHNIELLA: SOME INFLUENCES OF AGE, PHOTOPERIOD, AND LIGHT INTENSITY

1970 ◽  
Vol 102 (5) ◽  
pp. 534-540 ◽  
Author(s):  
R. M. M. Traynier
Keyword(s):  
Sex Pheromone ◽  
Light Intensity ◽  
Organic Solvents ◽  
Sexual Behaviour ◽  
Light Period ◽  
Unmated Female ◽  
Diel Cycles ◽  
The Mediterranean ◽  
Old Females ◽  
Mediterranean Flour Moth

AbstractUnmated female A. kühniella (Zell.) emitted a sex pheromone at the beginning of the light period of a 24 hour cycle of light and dark periods. There were no differences apparent in the duration of the calling posture by females in light of 1, 40, or 200 lux. A sex pheromone was extracted from the abdominal tips of unmated females of various ages with organic solvents, 3-day-old females gave the most potent extracts. Extracts of equal potence were obtained from females at different times during the diel cycles of photoperiod. The response of males to the extract was maximal at dawn, increased with age for 5 days, and was greater in light of 1 lux intensity than of 200 lux. Both sexes showed an anticipation of the beginning of the light period in their sexual behaviour, but if the timing of the cycle of photoperiod was changed the behaviour of both sexes became synchronised to the new cycle on its second or third occurrence.

Vigilance states, EEG spectra, and cortical temperature in the guinea pig

1993 ◽  
Vol 264 (6) ◽  
pp. R1125-R1132 ◽  
Author(s):  
I. Tobler ◽  
P. Franken ◽  
K. Jaggi
Keyword(s):  
Guinea Pig ◽  
Rem Sleep ◽  
Guinea Pigs ◽  
Process Model ◽  
Dark Period ◽  
Nrem Sleep ◽  
Light Period ◽  
Recording Time ◽  
Cortical Temperature ◽  
Eeg Power

Vigilance states, electroencephalogram (EEG) power spectra (0.25-25.0 Hz), and cortical temperature (TCRT) were obtained in nine guinea pigs for 24 h in a 12:12-h light-dark (LD 12:12) schedule. Sleep was markedly polyphasic and fragmented and amounted to 32% of recording time, which is a low value compared with sleep in other rodents. There was 6.8% more sleep in the light period than in the dark period. EEG power density in non-rapid eye movement (NREM) sleep showed no significant temporal trend within the light or the dark period. The homeostatic aspects of sleep regulation, as proposed in the two-process model, can account for the slow-wave activity (SWA) pattern also in the guinea pig: The small 24-h amplitude of the sleep-wakefulness pattern resulted in a small, 12% decline of SWA within the light period. In contrast to more distinctly nocturnal rodents, SWA in the dark period was not higher than in the light period. TCRT showed no difference between the light and the dark period. TCRT in REM sleep and waking was higher than TCRT in NREM sleep. TCRT increased after the transition from NREM sleep to either REM sleep or waking, and decreased in the last minute before the transition and after the transition from waking to NREM sleep. Motor activity measured in six animals for 11 days in constant darkness showed no apparent rhythm in three animals and a significant circadian rhythm in three others. Our data support the notion that guinea pigs exhibit only a weak circadian rest-activity rhythm.

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